Camped in a conway cruiser many times in the cold and it was warm enough. Only worry we had was getting the canvas dry if it rained as drying takes longer in the cold damp winter months. We always used the fitted electric fan heater. Only thing that was cold was the draughts! I agree with previous posts - be more scared of the wind - it can be a killer for any age of tt or fc - plus it is noisy and the camper rocking in the wind is no fun at all!
There are some great replies to the question, we use a fan heater, but they are noisey at night, even after a few pints,plus vino.I was thinking about an oil filled rad, so I will get one.Our earliest camp is the first May bank hols, usualy around the Scots borders, but this year hopeing to go farther north, but not if its snowing!
talking about the best time of year to go...who can tell. When we went Aug bank in the Peak District this year, it was FREEZING in our tent at night..even hubby was cold (unheard of!). We were on a bit of an exposed site unfortunately, fab views but I have NEVER been so cold at night! Neither have our friends and they are hardened campers! worst of it was we had taken my 16 yr old daughter's, and she isn't used to camping in a tent on an air bed..they have a trailer tent and only do caravan club type sites......think it was a bit of a shock, especially as the toilets were a bit of a way awy across an unlit, very uneven feild of long grass, with a pond in it!! Have to say, that holiday, coupled with our very very wet Devon camp in mid August made me buy a folding camper...want a bit of luxury for a while now!! Roll on summer!!!! (or even Spring!)