While I don't get snow where I live from everything I've heard the Tesla does quite well despite being rear-wheel drive due to how smooth the electric motor is. I also understand the 19" tires last quite a bit longer. The 21" summer tires are crap in cold weather and especially in snow. I had to drive from Reno NV to the Bay Area last March and hit snow coming down and it wasn't too fun, especially since the 21" wheels cannot use chains. The traction control on the Tesla is better than most cars since the electric motor is much more responsive. I read that the TC is able to monitor and control the wheels around 1000 times/second. My experience is my model S is a hell of a lot better than the Toyota I used to drive. That car would lose power for a good second if I so much as ran over a pothole and good luck if a tire slipped on snow. My model S P85 is able to keep the wheels just on the edge for acceleration.
When I was driving back the snow was starting to really come down. I had just beaten the chain requirement. It was not fun with my tires but none of the problems were due to acceleration or traction control, more just from the fact that the tires had no grip and given that fact the car still did fairly well. Driving up to the summit to try and beat the snow was fun though. That car doesn't seem to care if it's a steep grade or not