When I first started in a journeyman program many many years ago I was told a story about how painters "in the old days" would actually pee in their paint to keep it from freezing in fridgid temps...I've never followed up on it, simply took the stories with the usual wink and a nod...
...Of course paint was formulated differently "in the old days..."
I can't think for the life of me why anyone would need to paint below freezing anyway...