I’m probably in the minority here, but I agree with you that 40K is a good target number. And “where” those seats are is vital. Most would agree that upper deck seating on press box side should be reduced (general admission specifically), replacing it with suites, club seating, etc. I don’t recall off hand the number of seats there now, but we probably lose 5K seats when that comes down. Walking to the top of that area wasn’t fun when I was young!
Anyway, we’d need to make some of that up, most likely in north end zone. That said, I do like some of the ideas presented in the survey for the end zone area.