I'm not familiar with bear habits in that particular area, but it's for sure not too late. Bears only den up when there's no food left, and with the mild fall we've had I'm sure there's still plenty of berries and forage for them to eat around Mt Adams.
That said, I bet prime season where they stand out in the open huckleberry meadows is probably done, but if you can find patches lower down, you still have opportunity. (I want to be clear this is just a guess; I haven't been to that area since last year so I'm not sure how the berries are doing at different elevations).
Good luck!