bazyar -
I live in Korea, not quite as much snow but alot of ice and very, very cold.
I too am attempting to decide what to do about winter. The wheel and tire availability in Korea is limited particularly on Michelin Pilot Sport 19" and parking my car just is not an option. There is a post not more than a week or so old wherein dicussion about 18" wheels all around is discussed. One of the original forum members jsisabella has placed 18" wheels on the rear with Dunlop Snow Tires. He also stated that he placed about 15k in the cargo area and the Crossfire drove quite well. Good news indeed. Send him an email, he has an active post regarding "standards." He is most helpful and I am sure he will give you further details.
Let me know what you decide to do. Since I live in a apartment building complex I am limited to the space. Therefore, I can't by an extra round of tires and spares.