Do you have thermopane windows and is the coach well insulated and you have electric hookup.
IF you have them than why not be comfortable and follow the link here
for camping in sub 0* weather.
I have camped in 1* weather with fresh water tank full and lived with out a hitch.
You will need to know where to get LP or diesel for your heater because time to be spent at location.
We have people traveling all over that live in the northern regions because they are working or skiing or what have you.
If you can't than you need to winterize and use water and anti as you were going to.