My understanding was that sites in the UK had to close for a certain periods each year to avoid offering permant places of residency and all the red-tape that follows.
A friend of mine has recently sold his house and is currently living in his (very luxurious) "van". He will have to be off site for a short while over Christmas but as he plans to divide his time between the UK and Australia it won't present a problem to him.
I think I would have to rent storage were I ever to make the same move.

C-flat.