The Nuway, propane stove works very well in a tent with a stove jack...the chimney vents the exhaust products and it really heats up an insulated tent very well... between -30 and -40C you start to lose pressure as the propane phase to gas slows down and at -40C and lower you might get very little heat even from a full bottle. Keeping the bottle full helps as does using a 30 pound bottle. After -30C moving to wood makes sense. The venting of the chimney makes accumulation of CO less likely and using a non vented heater is a bit more risky.
For a non vented source ensuring clean burning and making sure you aren't cooling down the flame with a big pot of cold water helps a non vented heat source like a coleman stove be a bit safer but always a risk. I used a coleman stove in Nunavut for a lot of years but wouldn't do it again. Too risky. CO can kill you.
I made a video on vented sources if you really want to geek out.
https://www.youtube.com/watch?v=VgoP9_Fj26w
