4 seasons toy haulers under 5000lbs dry weight?

I've done 20s regularly (with above freezing daytime temps) in a TT with a slide (now Theres a leak point) so i wouldnt think that would be a problem for you as long as you are careful with your water/fluids. I seem to remember seeing a couple of models recently that advertised ducted/heated underbelly. Sorry, cant rem what they were but the were in the 21-22' range.