Class C quality with heated underbelly, double pane windows.

Consider a Lazy Daze 27 foot model (a couple different floor plans). The cabinets are first rate, no particle board. The windows are double pane standard, not optional. There is a queen size cab over bed and main floor couches/beds as well. I don't think the pipes are enclosed, but extra insulation is available as an option. Many on the west coast take theirs up into the Sierra for cold weather camping. Good luck with your search.