Has anyone used their eurovan or westy for camping in the winter?

Say you were in the mountains for a few days and it was below freezing do you
need to worry about the water lines freezing?  I assume you would have to
empty the water out and put in antifreeze.

This would be a hassle if travelling during the season when it is warm in the
day but may go below freezing at night.

Any opinion or experience would be appreicated.

Chris and Marion
1995 Eurobago