c,
A few years ago at Chatsworth C.C.site over Christmas and New Year we had temps down to -8C for 3 noghts and a max of 1C during the day plus snow. On the second morning of these temps at least 15 aqaurolls had frozen solid. The warden allowed all the frozen ones to be put in the laundry which was heated to 70F.
It was quite amuseing seeing all these frozen ones with their water pipes sticking out of their tops.
From this i learnt a lesson. If the temp is going to drop below freezing, fiill the kettle before going to bed and put some water in another say 1 gallon container, and then disconnect the aquaroll and put it in the awning or if no awning empty it and place it outside the caravan door to fill in the morning.
Bring the pump inside the caravan.
If you have an inboard tank, as we do, then make sure the tank is full at night and just empty the aquaroll.
If you fully insulate the aquaroll you may get away with it but do not forget to insulate the pipe from the aquaroll to the caravan.
Hamer