Only you can decide whether taking the risk is worth it for you. But if you're going to do this, one thing you might want to do is build in a longer connection than you normally would.

I did this a couple years ago with a ticket on United to YYZ, then a ticket from YYZ-LHR on UA ticket stock, operated by AC (with several segments around the world over the next few weeks). Thunderstorms in YYZ that day caused massive delays. I tried to get AC to move me to a later flight proactively, but they refused to do anything, even if I offered to pay. Luckily I found a sympathetic United Club agent who worked with reservations to move me to the later AC flight. In the alternative, it would have cost me $6k to fix the problem.