| RE: All season or snow tires?
All season tires are a "compromise" between summer/winter performance. They will work for you in winter, but to get best performance in snow, you will neet snow tires. I'm sure you will see lots of snow in Canada.
I drove a front-wheel drive Honda Accord on all season tires in the NorthEast U.S. for a number of years. I finally switched to snows & could not believe the difference. The Accord had the same grip as AWD SUV's/pickup trucks.
Going one size larger is OK, as long as the diameter remains the same. | 
