Well if it was doing that in the summer then your jet may actually be spot on for the cold Temps. Good too since 4ting in the summer keeps the engine cool enough, meanwhile you got the air to do that for you in the winter so a tiny bit lean wouldn't even be an issue.
I suggest just riding out the storm till you notice if it's too hot or not. Plug checks are going to be the most definitive way, at least they are easy to do on these uncomplicated machines (busted a freeze plug on my truck so I'd much rather be having bike issues right now lol...)