Okay, I just counted all the September US leg shows. These are very round numbers, and I may be off by 100 or even 300 on Detroit, but here's what I came up with over the past hour.
GA's obviously not included.
Minneapolis - 650 tickets remaining
Indianapolis - 2500 remaining
San Diego - 4500
Detroit - 4500
Kansas City - 5800
Buffalo - 8000
St Louis - 9600
New Orleans - 11400
And for the heck of it, New York 2, coming up in less than 2 weeks - 1100.
Obviously we have seen tickets pop in and out of ticketmaster, sometimes huge sections all at once. So maybe a lot more tickets will be available for Indy if you look tomorrow. (Or 20 minutes from now.)
If that Indy number is right, then they shouldn't have any trouble selling out by showtime. Might need to lower a few prices the week of, but it should happen.
San Diego and Detroit might sell out by showtime. It won't be easy though, and they may need to lower some prices sooner rather than later.
It's also possible that we'll see a few tarped-off upper deck sections in places like KC or Detroit like how they did it in Pittsburgh. But if they aggressively try to move those tickets, then San Diego, KC, and Detroit may not need to resort to that.
At this point, it would be a shock if Buffalo, St Louis, and New Orleans didn't need to use the old tarped-off sections trick. The quantities they have remaining are fairly large.
Finally, it looks like they've already started instituting some "aggressive" pricing strategies, as I spotted a few stadiums with $35 tickets available that I'm pretty sure didn't have them available a few days ago. So they took some of the remaining upper deck inventory and marked it down from either 70 or 100 down to 35.