Hi all-

So I have a mixed cabin award situation on a late August trip, SEA-YYZ-ZRH, where SEA-YYZ is booked in Economy due to lack of C *A award inventory at the time of booking.

1) I realize I have to basically keep checking to see if inventory opens up for this flight, but is there a rule of thumb on when to check? 90 days out? 30 days out?

2) Do I stand any chances for an upgrade at the airport? I asked AC directly about waitlisting, but they refused saying UA needs to send an OSI (Other Service Item) for the airpot agent to review. UA says this is not something it can do. Do I just ask the AC check-in/gate agent to add me to the list? I assume my priority would be at the bottom after all the AC elites, but I guess it wouldn't hurt to ask?

Thanks!