Carol,
I agree with previous comments. In cold weather like in the 40s and lower, the 110v heat strip works well to maintain a given temperature, but waking up in the midddle of the night to a cold rig, the main propane furnace is the right choice. Unfortunately when it comes to heat and air conditioning, motor homes are extremely noisey, worse than being on the open road.
The 2350's rear corner bed window side position is going to be a cold spot if you don't have thermal windows and shades drawn. I would cut a bubble wrap foil automobile windshield sun shade to a size that can be pressed in place and seals well to the glass on the inside. The same goes for the sealed rear window.
Having a small 1500 watt electric space heater placed by the entry door will maintain a temperature and block cold air coming from the front cab area. Many such models are very quiet. The ceramic heater type seems ideal for the application, and they are very compact. Of coarse you will need shore power to use it.
If you don't have shore power, then you are completely dependant on the propane furnace. Just be sure that your batteries are well charged before going to bed. Though the furnce is propane, it does use 12v to blow the air around, and that blower is a power hog. You may wake up in the morning to a cold house, dead batteries, and a dead fridge. The furnace blower drains the batteries during the night, then the fridge which also depends on propane for the cold, and 12v to control it, it too dies. It's not a train wreck. You simply have to run the generator to get all things working again, but it takes many hours of generator run time to bring the batteries back to full. That is why I carry a smart 40amp battery charger for just such occasions as it reduces the generator run time astronomically.
You may find my post on conserving battery reserves very interesting.
CLICK HERE then scroll down to the 3rd block and you will see my 40amp charger in action.