It seems strange that the bedroom does not have it's own vent?
On my rig, with the front bedroom, middle living/kitchen, rear bath, the bath is the only 'room' that does not have it's own vent because of where the entry door for the rig is..
I only have 2 vents. One in the middle and one to the bedroom.
Normally, I don't like to run the gas furnace as it's loud and uses a ton of gas.. I always have at least power hookup at the sites I go to, so we have a small electric heater that I'll use in the living area. When the door to the bedroom is closed, no heat really gets in, but usually the comforter and shared body heat is fine..
We close the bedroom door because all the LED lights that stay on makes in the living area makes it really bright in that room. So much so, you don't need any lights on when going to the bathroom in the middle of the night.
Anyway, is there anyway you can add a furnace vent to the bedroom? I know when I use ours, it really heats it up nice.. It's just loud when running.. My furnance has about 4 unused 'cutouts' that can be used for additional vents. It really blasts the air with only 2 of them being used!
Good luck! Mitch