Many cabins/lodges are on holiday parks that don't permit all year occupancy, so they're not allowed to rent out the properties for a couple of months of the year. That nearly always means that they're not available in January.
However, to the best of my knowledge, the excellent (multi-award winning) Cliff House Holiday Park at Dunwich, here in Suffolk, has properties available all year round. It's a small, very upmarket site, right on the clifftop, with a number of cottages and lodges (furnished to an incredibly high standard) available for rent. The bar and restaurant are also very 'classy', often being used to host smart wedding receptions.
My friend has stayed there lots of times, with me providing her with transport to and from the site. (That's how I've got to see the insides of the properties and to enjoy the food and drink in the bar/restaurant).
The AA Routefinder calculates the distance from Guildford as about 150 miles, with an estimated driving time of around two-and-three-quarter hours, so it's well within your reach.
Link here:
http://www.cliffhouseholidays.co.uk/self-catering/lodges-and-cottages
(That's the first of two pages).
The Suffolk coast is beautiful at any time of the year, with the attractive little village of Dunwich being just down the coast from Southwold, which many people regard as as one of Britain's most delightful coastal resorts. Worth a look, perhaps?