In recent years it has been played at Glen Abbey, Hamilton, Shaughnessy in Vancouver, St. George's in Toronto, Angus Glen just outside Toronto, and Royal Montreal. Many of the best Canadian courses would be challenging from an infrastructure and fan base perspective but I do think they could make a bit more of an effort to get some variety and move it around more. Part of the problem is the current date right after The Open Championship, so when it goes to the west it is a very challenging trip for players who have competed in Britain the previous week.
I have played Glen Abbey and it is a tough course for guys like me but only the valley holes are particularly memorable. Still, it would be unfortunate if it became a housing development, although I imagine given its location it would be quite valuable for that.