Fruit set still depends upon your temperatures, even if it has ‘cooled off.’
If your nighttime temps are still above 70, that’s part of the problem. Also, how’s the humidity? High humidity causes the pollen to become ‘grainy’ and that prevents good pollination, too.
If it were me? I’d leave them in the ground, keep them watered and give them a shot of fertilizer. You should still have plenty of time in Zone 7 to produce a late crop of tomatoes, I’d think.
I do have 2 in the ground, but all the rest are in containers. Will do as you & the other gardening FReepers suggest, regardless. With as crazy as the weather has been this whole year, who knows? There may still be a chance for fruit-setting up to Nov. :-)