Just curious about your SAN-YYC. That's the AA code on Westjet? Why do that rather than book actual AA and fly in domestic F/J rather than Y?
Yikes! Where are you seeing that it's Westjet? It comes up as operated by AA on the OW booking system and Kayak.
Many of us do this every year. I've even done a second one in the same year. I almost always book about 10-11 months before my first flight, using dummy dates for every subsequent flight, and then change as the booking window opens up. Usually, D is easy to come by when booking far out. There have been occasions where D is not available (e.g., HKG-HKT or HKG-DPS or sometimes QF routes). You can waitlist for D.
So good to know! Thank you!