We are staying with my parents between Christmas and New year, but so are a number of other family members so beds are somewhat stretched. The children will be staying inside my Mum's house, but DH and I are considering sleep on the drive in our Bongo. How cold is it going to be?! Are we going to get hypothermia?? Any tips for how to keep warm....or should we find a nice warm b&b...?!?!