Thanks for all the replies.
I don't think covering is going to happen.. I probably can't put up a car port and get it into it's parking place. I also am resisting the idea of get a soft cover. First, it's normally on the truck and the covers I've seen don't seem to be made for that. Second, and most importantly, it seems like it would be a big disincentive to using it. Our plan is to get out at least every other weekend if not more and climbing up in the rain to put a cover on and off seems like a major pain. One of the advantageous of the TC (from our old pop up trailer) is that it is ready to go at a moments notice.
I don't know, I might be making a mistake, but I think I'm going to try it without the cover. UV is certainly not the issue out here in winter.
From other replies I think I'll go with a small electric heater (we have a 120 volt connection) and maybe a vent or two cracked open.