I guess you'll just have to take my word for it. ESPN Classic showed the '83 Grey Cup about a month ago, cut down to two hours. I decided not to torture myself by watching it again.
By 'works' I mean the NHL Network produces a fairly respectable on air product, as I see it as a viewer. I'll leave profit margins and ratings to the bean counters.
I don't think anyone is suggesting TSN give up its live game broadcasts, but a CFL Network could show game replays throughout the week, as the NFL Network does. Combine those with classic games (maybe one from a certain decade for certain nights of the week), Top Ten shows TSN has produced in recent years (hardest hitters, colorful characters, top GC moments), and the Engraved on a Nation series. Filling air time will always be a challenge, but I think there's definitely some material to work with. ESPN Classic gets away with showing three hours of Kiana's Flex Appeal every day!
I doubt it would be a big money maker, but a good way for the CFL to market it's product, and as hypothetical partner, give TSN an opportunity to justify, or hike its cable package.