Originally Posted by drewguy

Last minute. I was in your situation last month. Sought upgrade about 25 days out--didn't clear despite all 9s for availability in biz and ~half seats showing open. Sure enough each day in the last two weeks there was a slow dribble down and down to where there were only ~3 seats at T-48. I saw R-space at 1, called, and cleared the upgrade.

That said, it all depends on when in the week you're flying--midweek less likely to fill up.