Can you maybe post a picture of your setup? I'm not completely following what you're doing.

Am confident you know that if you can keep the fuel temp above 50 degrees or so you'll get normal performance from a vapor feed setup. If the fuel gets much below freezing, you'll use the propane fraction of the fuel first, perhaps losing functionality before the canister is empty. Of course there's no way of knowing this while it's burning happily.

Really, it's just a balancing act of capturing enough heat to keep the canister warm but with no risk of getting it hot. The simplicity of a canister-top stove is welcome in winter, when you'd really rather not be fiddling with a complex stove rig.

Good luck with that back! Cold weather seems to trigger all sorts of bodily maladies.

Cheers,