It's not too fun. In December, flying from Halifax to Toronto necessitated waiting from 8:30am to 3:30pm to find out that our flight was cancelled, and subsequently waiting until after midnight to depart on our rebooked flight. This rebooked flight routed us through Montreal, so we sought and found a quiet area in the departure lounge at Dorval to "sleep" for a bit before our 6:30am flight to YYZ. All in all, we spent about 24 hours from arriving at the Halifax airport to arriving at Pearson. It wasn't *that* bad, and I can't blame the airlines for the weather or icy runways (and unlike WestJet, Air Canada has many more flights on more routes, along with a "secret" reservations line for relatively quick re-bookings), but I'd sooner fly in the summer or, well, at any time of year apart from Dec/Jan.
The trip back was a dream in comparison. I had a brief stopover in Ottawa, whereupon I was called to the gate as I evidently needed to change seats. They put me in executive class and, as ever, the Seinfeld depiction is almost wholly accurate (though my meal was just a light lunch).