Model S does not need snow tires
I like several others on this forum have gone through back to back VERY tough winters in New England with my Model S with the stock all season tires. To put things in perspective for others in the world, in the last 3 weeks we've had storm(s) of 34+, 24, 20, 18, 16 and 6 inches.....yes that is over 100 inches of snow....in 3 weeks. Cars are buried everywhere and road conditions have been aweful (2 lane streets reduced to 1 lane). The MS with stock tires does not has never spun out, lost control, or got stuck....unlike the SUVs or front wheel drive cars on the road.
So, because of the amazing stability & traction control of the electric drive train of the car, it has handled these horrible horrible conditions without any hiccup. We can even go up slushy hills (where you cannot see the ground) albeit in a manner I've never seen before in a car. I also debated about getting the Michelin ICEs last year but wanted to test out the stock tires first, never needed to. I do switch out the stock all seasons for 20" aftermarket extreme performance summer tires though.