said by Lurch77:Wheel size has little to do with snow and ice traction. .
Dear Friends,
Although contact patch shape does, thus the preference of some for the sixteen inch wheels.
I have no issues on light snow with my MX5(Mazdaspeed 04) but the limiting factor is ground clearance at some point. Driving a car with six inches of clearance on ten inches of snow is no longer a question of driver skill.
That said, my own preference would be to go for separate wheels and tyres as it is ultimately, from someplace like tirerack.com cheaper, and, given the patch shape, safer.
All good wishes,
Yazdzik