Northwood does not run heat ducts up into the cabover area like some of the other manufacturers do. Our cabover tends to stay a little cooler than the rest of the living area. We like the fact that it stays cooler for sleeping. I also have thermal panes but it still gets cooler as I said.
We do run our Wave 3 heater and it tends to heat the lower living area better than the cabover so not sure if that will help make your sleeping area warmer.We do really like ours and its nice and quiet. Seldom do we have to have that loud furnace running.