With the 19" stock wheels and tires, you should be fine. The current production is shipping with Michelin All-Season MXV4's I think. You would not be fine if you went with the 21"s like me ... those come with summer tires only, but hey, I live in California. It's only partially about AWD-- the tires you have are important too so make sure they say All Season or "AS" when you get your car.
Unless you're planning on driving in severe ice storms with 6 inches of snow on top, this will do just fine. Then again, if there is a severe ice storm with 6 inches of snow on top, even if you had a Hummer, I would urge you to wait it out and drive once conditions improve ... you know, for safety.

I came from a much colder place once upon a time.
- K