Potential RV'ers from Alaska

My sister and husband want to RV for winter in southern US, but are afraid to leave their home in Anchorage for fear it will freeze up over the winter. Their concern is based on using a boiler to heat their home, and they are concerned about HOW TO take care of it so they can relax and enjoy being out of the cold. I told them that I would see what others are doing that come from like conditions.:h
any help/guidance appreciated