I left Canada in 2008, and I don't remember chip & pin being prevalent as it is now, so it's not quite as "long ago" as you are implying.
But... you might have issues carrying just a credit card. Many places only accept debit due to there being smaller merchant fees and there are still many cash-only places (in Toronto at least).
And seriously? When I end up with cash / change in my pockets I end up using it. Your comments about "OMG! What do I do with physical money?! It's sooooo useless" are a bit hyperbolic.
