My original post is right here, but below I have a subsequent query--in case anyone has the answer. Thanks!

I am looking at J availability for tomorrow's AC850 (YYC-LHR). Do the 4 J seats showing free on BD count in the J7 total I get when I check AC's flight load, or is the actual number of free J seats 11? I am hoping to score upgrades for DW and myself and am wondering about what the actual numbers are. Do BD seats eventually get released to AC, or do they just go empty at flighttime if unsold by BD?

One other question: I get that I need to get us back on the waitlist once 24 hours prior to flight time has passed. However, can I call that in or do I have to do that at the airport, and if the latter case, can I do it at any time tomorrow (eg I have to go right by the airport at 7:30 a.m. tomorrow so could pop in but do not fly until 5:10 for my YQR-YYC flight)?

I've never had to do the aerolotto thing so am a little iffy on the exact details (despite the very helpful faq on this).