One thing I have learned from the AC forum is "If, at first, you don't get a satisfactory answer, hang up and call again."

Learned this the hard way on Thursday. I was booked out of YYT on 691 en route to HKG on the 8th, with a "wind warning" in the forecast. I was checking flight status after dinner, and Flightaware showed a cancellation of the 5am departure (while it still shows "on schedule" on ac.com). Once the AC site caught up and showed a cancellation, I called reservations immediately, as flights out of YYT have been fully booked all around the start of the long weekend. The first agent I spoke to said it was still showing on schedule, and it took a couple of minutes to convince him to check with someone else; indeed, it was cancelled. I had a confirmed upgrade on 007 that had just evaporated. He basically told me the only option was a rerouting out of YYZ via NRT. I said I needed to think about it and call back. Hung up, called back, got Kaitlin. After explaining the situation, she said "let me work on it," and after about 10 minutes came back on the line with an option through YVR and NRT, with an upgrade on the latter segment. I was impressed, and had not expected to be able to get this.

As it turned out, 693 (upgauged to a 321 to accommodate 691 pax) was delayed out of YYT (check-in took forever, it was definitely understaffed). So, I missed 181 to YVR (plane was being pushed back when I got to the gate). Was offered Y cabin through NRT, or travel the next day through YVR and upgraded (again) on 007 on the 9th. Opted for the latter and am sitting finally in the Int'l MLL at YVR awaiting the flight. Oh well, I was very impressed with Kaitlin and have sent a message to AC commending her diligent effort and real attention to customer service. It felt like concierge service (was SE last year and will be again next).

Lesson reiterated - if you get an agent who doesn't care much for the job, hang up and call again.