What I do is, I put an empty super under the bee escape board. I worry about the same thing, where will all the, seemingly overpopulation, bees will fit.
Was thinking the same thing. Golden rod is just starting to bloom. Do you think they can get a deep drawn out and full before winter?Pull the supers, put on another brood box with undrawn frames, let them get to work drawing comb. Even if you aren't planning on it for winter, use the bee force you have now to increase your resources.
You've got winter honey stores for them in the super you were going to leave right? So it doesn't matter. You are doing it to give them space and something to do. You've got a strong worker force, the brood nest is shrinking, and idle workers gotta do something. May as well let them build useful comb instead of putting it below, above and between the frames. What frames do you need the most? If you need deep frames drawn put a deep box on, if you need medium frames then do a medium box. You'll be pulling that new box back off in three or four weeks. Whatever they completed is a head-start next spring. Use a queen excluder so you don't get any brood up in there that will keep you from pulling it back off in a few weeks.Do you think they can get a deep drawn out and full before winter?