To me, a 3-season camper is ready for spring, summer and
fall. Our small
Scamp is pretty well insulated and two warm bodies keep it comfortable. My bed has many layers of comforters and blankets ready to use in all kinds of weather. Of course, we dress in layers as well. Our shades, made of black out material called Roc-Lon, keep out
light AND insulate all windows and roof openings. Yes, it's nice to have a fuzzy area rug, that can be washed, on the floor in cold weather. I like the floor bare in warm weather. The heater takes the edge off in cold weather. Now that I think of it, the only change I'd make for freezing winter weather is to remove all water from tanks and pipes and use free-standing water containers so as to prevent frozen pipes from bursting.