They had a two-week handover period at the motel, and Frew is computer-savvy and has previous business experience.
The two have hit the ground running, with a leap to four-plus stars for parts of the accommodation and a Qualmark bronze award for environmental sustainability earlier this year.
"I just think it's probably our personality and willingness to learn something new and try and get ahead," Frew said.
Six casual staff and their motel minders had contributed to their success, as had the 7-year-old daughter who lives on site with them.
"The guests think she's fantastic."
In their voting comments, guests talked about the motel's blue lights, its friendly staff, its clean, modern look and its children's play area.
151 on London has a conference venue that seats 80 to 90 people and is used once or twice a week, Frew said.
The accommodation sleeps 73 people and averages 50 per cent full.
A 20 per cent increase in occupancy has occurred since Frew and Gill bought the business. It is already 75 per cent booked for January.
Buildings on the site are owned by Steve and Karen Rowe, and are for sale at the moment for $2.2 million. Frew and Gill thought about buying them but instead have added some of the motel's distinguishing flourishes - the blue lights, new signs, pebbles for the gardens, a fish tank at reception.
Being close to Garry Kristiansen's popular Kristy's Cafe, SH3 and Wanganui Collegiate School could also work in its favour.