I don’t think the freezing hurts. I had two different sets of smooth on cans in my garage and both were exposed to freezing temps for a short period. One set had just can scrapings, the other nearly full.
I had a stack of overlay material and a couple boards that I was gonna glue together. Thought it was a perfect time to use up the can scrapings. Now the A(white) side seamed just fine, but the B(yellow) side seemed a little thick, almost gritty. I went ahead with the glueup, but after 3 days at room temp they still hadn’t completely set.
So I trashed the overlays and cut the boards back apart. I then went to the nearly full cans. Both parts seemed fine, mixed well and set completely in under 24 hrs.
Now I haven’t done a complete glueup, but I did flex test both sets of overlays. The ones glued with the “gritty” mix blew apart with failed glue joints. The other set flexed further than I thought with no issues.
So even though it is a two part epoxy, I guess the B side has a shelf life especially with lots of air exposure. Mine were nearly a year old. I will admit, the lids were probably not completely sealed on the partial set and allowed air in.