Don't bother to try using the spray version outside in near freezing temps. Had a minor leak between the Chimney and the roof last winter and attempted a temporary fix before getting a professional in.
Soon as the aerosol hit the cold air, the whole can just clogged right up. I probably should have known that going in, but just a word of warning, depending on what you're using it for.
With a previous house I was able to repair some leaky skylights when using in the right conditions. Didn't own that house very long after, so not sure for how long those repairs actually held up for. I also think I used it in combination with some roofing caulk, so wasn't depending on only the Flex-Seal for that fix.