I don't have to worry about water freezing as the whole of one under-settee seat is full of one large reservoir (180litres) UI also carry spare bottles in case my electric pump packs up... You can put non freezing stuff like cables, hoses, watering can, waterproofs, shovel etc etc in external lockers without worrying about frost.
180ltr tank ...wow thats a big one ....180kg when full :cool1:
before anyone else jumps in... yes I have a reputation for liking a big one..... :banana:
Looking at your plans Mark, I would say that it seems you are going gas-less?
I would be interested to see how that works out, have you run like that before?