Not backcountry, (Base camp) but I used a Buddy Heater on my nylon cabin tent. (Lows in the upper teens to low 20's).
I have my connected on a long hose and connect to a 11 or 20 lb bottle (Located outside to conserve space). Nothing sucks more than running out of fuel during the night! It definitely takes the chill out, but won't work well to dry clothes. Propane heat doesn't seem to dry like wood heat. If I had a stove cutout in a tent, I would choose wood.