I saw a ton of wheel options for the 17 inch option. You don't have to worry about swapping out a winter wheel/tire with a summer wheel/tire diameter-wise because they have to be essentially the same, or else your speedometer will be too far off. Any 17 inch size TR offers will be identical to any 18 inch diameter (less tire diameter to account for the bigger wheel of the 18). I WOULD, however, be concerned about putting a different compound tire on (either summer with winter or winter with summer) because that would lead to some extremely interesting handling dynamics. If you're interested in maximum safety and snow performance, then go 17s with 205s.
MCS : ZHP