I just had the very same issue, crashes around Windhelm while using wet and cold, the same wetcoldbreathfrigid.psc came up in my logs. I've had very stable gameplay otherwise using wet and cold, even around Windhelm. LOOT-ordered, cleaned my masters with TESEdit prior to adding any mods. I did change fExtraTaskletBudgetMS= from 800 to the default 1.2 after realizing it caused large battles such as with the civil war quest to lag to less than 1fps. I've not found the actual source of the issue, but I am going to try disabling the wet and cold breaths and see if that helps.