the butane ( blue) gas freezes I forget the temperature, most folk moved onto (red) propane in winter if not using electric hobs, ect.
air blown heating
the pop insulation idea was mentioned and wrote about on this forum. was it windscreen silver covers used in the adaption?
Poptop blind
Eriba pop-top thermal insulation
not sure how the 2018 toilet flush system works but that may need checking hasn't frozen..
jug and bucket defrosting, water collecting
hot water bottle,
gloves / scarf / hat, thermal under clothing,
mop for floor if wet out,
floor mat for wet shoes,
hot chocolate,
get a grips for shoes in icy conditions,
micro fibre cloths,