The two previous posters, have more experience than I with a class c in the cold, though we could talk (a lot) about 5erโs.
That said.... we didnโt want to do extensive ( have too many projects now) modifications, so we went with the Bigfoot Class C. The previous owners (avid cross - country skiers) used it (ours now) down to -17 F, with the water system filled and useable.....with very minimal modifications. The โonlyโ thing that they did was to put a little โfoil bubble insulationโ in a few โstrategicโ locations, mostly inside the outside bay access doors.
We wanted to test it ( to well below 0 F)last winter, but used it only down into โsingleโ digits! No problem!
Several of the reasons we went Bigfoot was, enclosed, heated tanks and dump valves, one of largest ( if not the largest) fresh water tanks in the class cโs, dual pane windows, and on the E 450 chassis ( many class cโs are on the 350).
The โBIGโ negative is that Bigfoot ( although back from the dead) went out of business in โ09 ( ours is an โ07). They, while back in business, no longer produce class cโs. Everyoneโs loss!
Todd & Marianne
Miniature Schnauzer's - Sundai, Nellie & Maggie Mae
2007 Dodge Ram 3500, 6.7 Cummins, 6 speed manual, 3.73 ratio, 4x4
2004 Teton Grand Freedom, 39'
2007 Bigfoot 30MH26Sl