I took the advice of many posts here and at
www.matrixowners.com and put on 195/65/15 (Michelin X-Ice) with Toyota steel rims (very important). Interesting that your dealer says not to go to that size. Mississauga Toyota double checked when I told them that that was the size recommended and they said it was fine. (They were concerned that it may effect the speedometer/odometer and perhaps the computer) My wife and I have gone there for service for many years and they have never steered us wrong. If storage space is going to be a problem for you, they will store your off season tires for $50. There seem to be lots of good winter tires out there but check out
www.tirerack.com or
www.1010tires.com. I prefer Michelin.