About 100 customers have now had their power restored as the wild weather eases, but the Napier-Taupo road remains closed overnight stranding many in Taupo.
Approximately 400 still remain without power across the Taupo Plains and parts of Hawke's Bay.
The NZ Transport Agency has reminded drivers take care and plan travel carefully as winter weather conditions mean many central and lower North Island roads continue to be heavily impacted by snow, flooding and road closures.
'We are reminding motorists to the drive to the conditions with rain, cool temperatures and the possibility of snow still contributing to challenging driving conditions," Neil Walker, Highway Manager, NZ Transport Agency said.
State Highway 5, the Napier-Taupo Road, will remain closed overnight. The detour route, via Gisborne or Palmerston North, will add four-five hours to your journey, so plan ahead, or delay your travel if possible.
The Desert Road also remains closed, with the alternative route via National Park open.
State Highway 2 Otoko to Matawai is currently open but impacted by snow, so motorists are advised to take extra care.
The Rimutaka Hill Road is predicted to have very cool temperatures and light snow flurries particularly around early to mid-morning when people are commuting to work on Monday morning. Again, if possible, considering delaying travel, or taking the train. If you are driving over the Rimutaka Hill Road, watch your speeds and be aware of possible icy and slippery conditions, particularly in shaded areas of the road. This advice applies to other roads throughout the region.
"As conditions can change rapidly, we advise people to check the latest weather and road updates before they get on the road," Mr Walker said.
The wild weather has brought down around 150 33kV poles, and about 50 11kV poles across the Taupo Plains, which is now covered in snow about one meter deep.
Unison Relationship Manager, Danny Gough said that around 200 customers remain without power, and the teams had to wait for snow to melt or be cleared before they could commence the restoration programme.
"Our affected network spans about 60km, all of which is covered in thick snow, and high winds blustering through the ranges.
"Along with the fallen poles, many are also broken, those poles still standing are twisted, and there are wires strewn across the landscape . It's real network devastation."
He advised those customers will likely face no power for about a week, and the team were working with the community to keep them as informed as possible.
"We have started calling affected customers to urge them to make alternative arrangements and will continue that tomorrow. We have also been liaising with Civil Defence, Federated Farmers, Dairy NZ, and Rural Support.
"We are all going to work together and try and ensure our community gets through this challenging time; which will also involve looking at where generators might be of most benefit for community welfare."
He also advised for those dairy farmers still milking, the Company advised they should organise portable generation if they can.
"In terms of the response plan, as soon as we can get access multiple gangs will commence restoration. We have arranged for our teams in Rotorua to come down to assist our Taupo crews.
"We have also been kindly offered assistance from our peers at Northpower, Electrix and Horizon.
"Once our Hawke's Bay crews complete restoration in the local network, they will make their way up north to assist."
The team has now completed their aerial assessment of the network, and has confirmed damage is severe for network areas that feed customers in Tutira, Patoka and Ridgemount/Pohokura, Puketiri, Esk Valley and Otamauri.
Mr Gough said those customers could be without power for a few days.
"We are committed to getting these customers back on as soon as we can, but damage is extensive, so we are urging customers to make alternative arrangements where they can, as well as reach out to wider support of family and friends.
"We have assigned about 10 gangs, as well as support from Centralines, across about seven sites to get restoration underway.
"We have about twenty poles down, but there are extensive vegetation issues and lots of wires lying across the ground. We also face very tough terrain in this region, so that will be the biggest challenge.
"We are working with Civil Defence who are assessing needs in terms of access, supplies and animal welfare. We have also been liaising with Federated Farmers, Dairy NZ and Rural Support to help our community get through this challenging time."
He said the team was very thankful for everyone's patience and the support that has been very well received by those in the field.
If outages occur through the middle of the night, he advised customers call 0800 2 UNISON in the first instance.
"Social media updates will resume in tandem with our crews at first light."
Customers can refer to Unison's website for advice on getting through power outages and electrical safety: http://www.unison.co.nz/tell-me-about/safety
Rain is easing but temperatures continue to plunge while more than 600 homes remain without power.
About 180 homes in Tutira are still without power, 89 people in Tangoio, 63 in Esk Valley, 12 in Puketitiri, 47 in Waipunga, and 25 in Patoka.
Another 200 homes in the Taupo Plains area have also been affected.
Unison said extensive damage had been caused, about 150 33kV poles, and about 50 11kV poles are down across the Taupo Plains, affecting just under 200 rural customers in the area.
Relationship manager Danny Gough said these people could be without power for as long as a week.
The weather bomb exploded yesterday bringing snow to inland areas, gusting southerlies, lashings of rain, bitter temperatures and thunderstorms.
"We understand this will be a huge frustration for these customers and we are mindful of the impact," Mr Gough said.
They were putting the call out to their peers across the industry for more support crews for the restoration effort.
"We have been overwhelmed by everyone's patience, and understanding of the impacts of the weather on our network."
The team were, by mid-afternoon Sunday, awaiting helicopters for access to assess final damage reports.
The coldest temperature during the last 24 hours was recorded in Te Haroto with Napier and Hastings temperatures expected to plunge in the next couple of days, Metservice meteorologist Stephen Glassey said.
"The minimum temperatures aren't that spectacular because you've had the rain and the snow and the coldest temperatures occur after then."
Rain lashed houses throughout Friday and Saturday with 66mm recorded at Hawke's Bay Airport.
Branches were strewn across roads in some parts of the region as strong southerlies chilled the air.
Gusts of 120km per hour were recorded at Cape Kidnappers on Saturday afternoon and Napier had 75km per hour gusts.
The skies lit up and claps of thunder could be heard rolling throughout Hawke's Bay as people stayed cosied up beneath blankets in their houses.
Mr Glassey said the thunder storm began at about 4pm and continued until 7pm Saturday night.
State Highway Two from Tutira to Wairoa has opened but has a caution in place due to flooding.
State Highway Five from Napier to Taupo remains closed due to snow.
Power was lost to most households and businesses yesterday with Hawke's Bay Hospital using a generator and Napier and Hastings cities closing down for nearly two hours until it was restored.
Police said there had been a total of 15 road incidents involving cars sliding and being pranged due to the wintry conditions.
A police spokeswoman said the number of incidents had probably not been as high as expected because people had listened to their advice to stay home and off the roads unless absolutely necessary.
Customers can refer to Unison's website for advice on getting through power outages and electrical safety: http://www.unison.co.nz/tell-me-about/safety. Updates are also available on its Facebook page.