We have a Montana Mountaineeer 324RLQ. I considered the Arctic Fox which is fine too. I am of the opinion that the 4 Season claims can be over-stated. If one plugs in the unit the underbelly, tanks and so on are kept warm and the water hose you use should be properly wrapped. The bunkhouse series used in Norther climes are usually better insulated but for most of us maybe/maybe a well insulated unit ie thermo windows too should work. Really depends on where you live. Our unit is parked on the West Coast which isn't that cold ie maybe 0 or a little less but for the really cold winters, boondocking is a challenge, to say the least. IMHO