Class A for winter

I agree that Holiday Rambler is a good choice as are any of the Monaco brands built in 2003 or before. I say 2003 only because in 2004 the Monaco brands shifted to fiberglass insulation in the sidewalls rather than the foam insulation, which is much better in cold humid climates. Dual pane windows are also great. Also as mentioned, 50 amp service is preferred. We travel mostly in the Winter and temps to zero and below have been no problem for us. We keep the fresh water tank close to full at all times and only hook up to the shore facilities to empty our black and gray tanks and to top off the water tank. If temps are really going to get low and stay there for awhile we use a thermostatically controlled 100 watt incandescent light bulb in the wet bay to keep the water lines and pump free from ice.
Many people will say that if you use your furnace, it will keep the water lines from freezing. That may very well be true but we very seldom will use our furnace and rely on electric heater and a heat pump unit. This has worked well for us in many years of Winter traveling in the Western mountains.