Potatoes are actually more vigorous in cool conditions. The limiting factor is frost free days, which could be a bit dicey in western Alberta, higher elevation and close to the Rockies.
Researchers have found that genetically identical seed potatoes yield higher coming from cold climates than those grown in warmer climates. The higher yields express into the 3rd generation.
Regarding scab, you may be right about organic material. Some varieties are resistant, Russet Burbank is completely immune to scab, perhaps due to the rough skin.