[Bill]

The furnace turns out an enormous amount of heat.  Believe me, staying toasty is no problem.  Beyond that, my experience in New England and high-desert Arizona, in single-digit and low-double-digit temps says:

Circulating the warm air to the rear bed is iffy if you close the privacy curtain.  Since there are just the two of us (plus dog and cat), we leave the curtain open, and we are warm as toast.  Of course, if you sleep in a front bed, you are golden.

The furnace's circulating fan is not silent, but it is not wildly noisy, either.  Do you live on a street?  Do cars pass in the night? Do you get used to the sound, so it doesn't bother you?  Same with the fan.

If you are dry camping (no hookups), then the circulating fan takes a certain amount of charge out of the battery.  One night of cold weather is fine, two nights is getting marginal.  If you plan to be out beyond that, I suggest you look up the thread on the Heater Buddy.

Hope this helps

Bill