Carquest,Autozone and Napa are all Mobil1 dealers,you should be able to get it at any one of those.
Does chain motorcyle parts retailer Cycle Pro do business up in Canada? They carry Mobil 1 V-Twin 20-50 as well as BelRay, some Spectrol, and other major motorcycle lubricants and chemicals. Always nice to walk into a "bricks-n-mortar" retailer with all the parts available