Utah or moving back after a couple years. The school isn't filled with morons. They could accept ten thousand more kids and I doubt that the acceptance metrics would drop. They still turn away kids who have 3.7 GPAs and 27s on the ACT. BYU isn't Arizona state, Utah, Boise State. There are some brilliant kids on campus and I would bet on your average BYU student to be smarter than a kid at Michigan or Texas.
Also aren't you the guy who complains about BYU not having a solid donor base? How would having fewer alumni actually help with that? I can see the argument if BYU was an ivy league school but that isn't going to happen. The world needs more BYU grads not less.