Air New Zealand is asking for more time to fly Kiwis home after the 48 hour 'Domestic Bubble' expires at midnight, tonight.
The airline's chief executive Greg Foran described Queenstown as a 'pinch point', telling RNZ this morning that up to 600 passengers may be unable to fly before the bubble expires.
When the move to Level 4 was announced on Tuesday evening, the airline said it had 800 flights scheduled and approximately 50,000 passengers across the network.
There are an estimated 15,000 passengers still to move today.
"Additional flights are operating out of Queenstown today and the airlines have upgauged aircraft where possible," said Mike Clay, Queenstown Airport's GM of operations.
"However, we know that there is more demand than capacity available today so there will be people in Queenstown and surrounds who are effectively stuck if repatriation flights are not able to operate after the cut-off this evening," he told the Herald.
This was mainly due to large numbers of leisure travellers in the Lakes area, and the airline was asking for more time.
"A lot of that is moving people in the South Island to the North Island, particularly to Auckland," said Foran. With many holidaymakers in Queenstown for extended breaks there was "a week's worth of travel concertinaed into two days."
Many of the return travellers were being redirected via Christchurch and Invercargill airports.
The airline said it was asking Wellington for an extension for the travel window.
"It's not unexpected," Foran told RNZ. "We've ended up with a lot of people in one location taking a week or two weeks holiday and are discovering it's been cut short.
"Apart from Queenstown we're in pretty good shape."
A big problem for the airline's schedule has been no-shows. With some travellers making their own way home, or choosing not to fly, this has made calculating capacity for the "bubble" more difficult.
"Some people make their intentions clear early, others change what they want to do," he said.
The airline asks passengers to manage their flights online where possible, as their call centres are under high demand.
Queenstown airport is currently only open to passengers and essential staff. Passengers will require proof of travel to enter the terminal, and should sign in using the Covid Tracer app.
"Our scheduled airlines will be operating on Wednesday 18 and Thursday 19 August to ensure people can return home. If you have a booking outside of the 48-hour window please contact your airline directly," said a statement from Queenstown Airport.
After the bubble: What to do if you still need to fly
Following the 48 hour grace period Air New Zealand says it will be operating a "very limited domestic schedule."
Flights from Friday will be for "essential travel" only. Passengers travelling after today will be required to carry a letter to prove their travel is essential - as outlined by the Government's Covid 19 guidelines.
If your travel is of an essential nature - you will have to call the airline's Contact Centre to rebook your tickets.
Other customers who are booked to travel from Friday will receive a cancellation email, and their bookings will be held in credit for 12 months, with another 12 months to travel.
From Friday, there will be just seven daily services on the network.
These are links between Auckland, Wellington and Christchurch. There will be one daily service between Nelson and Wellington, and Christchurch to Dunedin.
From midnight, physical distancing will be required by the Ministry of Transport on aircraft under alert Level 4, further reducing air capacity.
Qantas owned carrier Jetstar said that its services would continue as scheduled until midnight, tonight. Previous level 3 and 4 lockdowns have seen the carrier ground their New Zealand services.
"We are currently reviewing our schedule and some flights may be cancelled whilst some services may remain in place to allow essential travel to continue," the airline said in a statement.
For more information, passengers booked to travel with on Jetstar should visit their travel alerts page
Those flying with Air New Zealand should visit their COVID-19 Hub