Well, I have 4 coatis (not white-nosed, but it's the same difference), and I live in Manchester…..land of cold rain, biting winds and often snow. They all cope fine, living in large outdoor enclosures, with their beds off the ground in unheated sheds. They have nice thick furry coats, which mean they're fine so long as they can get away from the worst draughts.
I imagine it would be similar with peccaries…..the pig family are mostly hard as nails!