I went through this for a YYJ-YYZ-YHZ trip I am taking in 2 days.
I woke up early to upgrade. It let me upgrade YYJ-YYZ but said it could not upgrade YYZ-YHZ until departure time -4 days.

I feel that I have paid AC more money since I am flying 2000 miles more than the guy who paid to fly 1000 miles from YYZ-YHZ. I feel that I should be entitled to upgrade a little earlier than the YYZ guy. We are only talking about 6-8 hours.

The flight was R=1 at _4 days and 8 hours. R=0 at the 4 day mark (ironic) I am still waitlisted, R=0, J=1 for the flight. My fingers remain crossed.