I just got my used Scamp
13 this fall
. Haven't used it much except for driveway camping, got some electrical
and plumbing work done on it to get everything in working order. Keeping it warm in my driveway has not been all that difficult. Usually one small ceramic heater on the low, 750 watt setting can keep it well above freezing. On the single digit and low teens nights, I added a second heater at the opposite end of the trailer and ran it part time on the low setting as well, and could easily keep the trailer around 70*. Saying all this to indicate that the Scamps, while not designed for winter use, are decently insulated. I've done nothing special with windows
to add insulation, which I understand helps a great deal. I did add a chunk of building foam insulation to keep the portapotty from freezing when sitting on the cold floor on the really cold nights. I have no extensive plumbing, just a fresh water holding tank (empty for the winter) and a direct gray water drain line outside. I've just used jug water so far - works fine for my purposes.
Where in Mi are you? I'm in the Thumb. You would be welcome to come check out the Scamp
13 if you haven't gotten to see one up close. Mine is a 1999, so a bit smaller (lower ceilings) than the current 13's.
Good luck with your research. LOTS of good information on this site.