I could've sworn I'd seen a thread on this before, but I couldn't find it. I'm flying YOW-YYZ-FRA tomorrow, and was wondering: is it possible to show up at YOW early and same-day standby (for free) on an earlier YOW-YYZ if I have checked luggage?

Similarly, I'll be flying LHR-YYC-YEG on the way back. What about standing by free for an earlier YYC-YEG with luggage if I put in the standby request in LHR (if even possible)?

In both cases, the transfer times are sufficient that I don't care enough to actually pay for a confirmed change, but catching an earlier YOW-YYZ / YYC-YEG would certainly be nice.