Yes, I've had the leaks as "transitory" - but I've also had ones that after attach and re-attach didn't reseal again. those were a pain! None of he times I've had a leak
have been at -30 - more like "cool weather - down to freezing or so" - I don't even *think* of the word canister stove if the weather is going to go much below freezing.

And as I mentioned, the spit trick works - if it's above freezing. don't to it below or
you get water in there and it'll make the problem happen!