Ahh yes the moisture.. not good! Still have all the windows, all but 6 (4 up front 2 in bedroom) have foam board over them and cover over with plywood, hope it helps next trip out. Last Jan was like a rain forest in there once we got the BB heater cookin', but then the interior looked like a bowling alley on wheels,at least we can isolate the heat to the front or rear of the bus as needed. Oh the joys of camping!
All else fails there are the snow mobile suits we use for winter M/C riding