My question- Has anybody used a small propane heater that uses the small green propane cylinders to take off the morning chill inside of the TC?
I wouldn't go to sleep with it on or leave it unattended, just run it a few minutes to take the chill off.
Any time you need to take the chill off, just boil some water for a cup of coffee. If you don't need coffee,just pretend and light the propane anyway.
As far as efficiency and safety go, there is no difference from using any blue flame heater - and weighs nothing and takes up no extra room.
Catalytic heater with low oxygen cutout would be better but they take up a lot of space and are expensive.
A CO - Carbon MON-Oxide alarm is a sensible addition to your safety equipment