Store Leftover Finish With Bloxygen - Inert Gas
cant expound on the cold temps...sorry. I can say that it does like to be warmed (no sparks, flames etc). I did just that and warmed the nekkid bodies, soaked in the urethane. Really changed things. Only did it once as its a PIA. Wood readily soaked up the sealer better than cool alot faster to as in just dip in and remove.