happyjack2 - I remember when we first started looking for a small RV, we started by looking at RoadTrek's. Just could not be convinced to spend the money for something I could not ever stand up in. Then we found our present unit the 211-S by Trail-Lite. It was advertised as having R-5 insulation. That is not really great, but very seldom do you see any RV manufacturer stating the "R" value of the insulation. My brother-in-law stated that it could be much better insulated than most as they are willing to state or brag about the R value. We have found that the furnace can keep the inside toasty warm down into the "teens". Our only complaint is the periodic fan noise in the middle of the night and the drain it puts on the battery.