Let's say that for whatever reason none of the labour day matchups could happen one year. If this happened, what "rivalries" would you have in place?
I would say the easy ones would be
Toronto vs Ottawa
Hamilton vs Winnipeg
Saskatchewan vs Calgary
For the 4th match I would say definitely Edmonton, though I could see arguments for either BC or Montreal being a bigger rival. However I think I would have to give the edge to Montreal due to all the Grey Cup games.