Depends entirely on the brand and the construction. Note that if there is a zipper, water can get in there, pretty much no matter what. So...
I tend to take good care of mine. Brushing them off after they dry (if suede) and ensuring I wipe them down (if leather).
The tricky thing where I live is that "weather" itself is possibly the least of one's worries. What's really damaging is the salt/ dirt combo that is used to keep the roads and sidewalks freer of ice.
If commuting in a car and parking in a cleared lot (or garage) I think you'll be fine pretty much with anything. If using to walk in winter conditions, I would go with a very trusted brand. Aquatalia, La Canadienne, and similar.
What ones are you looking at?