I have been to Iowa games @ Ann Arbor, East Lansing, & Columbus. I would like to point out that with the exception of East Lansing, I never really seeked out the craziest area to drink with tailgaters...in fact, East Lansing was so lame that we parked our case o' beer 20yds from the port-o-potties just so we could people watch.
OSU was the closest I have observed to UI, that is, people walking around drinking (and with the exception of a few stupid college students, all super nice). I wasn't super impressed with Ann Arbor as it was more laid back, have 2-3 before the game, grill fresh game, and get on to whatever else there is to do up there after a Football game.
I will say, not in any of those cities, did I experience anything like walking down Melrose on a Sat am. There were a ******** of people in Columbus but not until you got immediately outside the stadium were they packed shoulder to shoulder.
I'm anxious to cross the other B10-11-12 or whatever it is now, stadiums off my list. Really looking forward to State College & Madison. & FWIW, with all the rules they are bringing on board this year, I see it having little effect on the overall ambiance of UI football games. Yeah, there will be the occassional d$*khead that will be upset & rant about not ever going to a game again but that is all hypocritical garbage...they'll still come. Hell, you probably aren't even going to be able to get student guest passes to games this year; and as long as that is the case, people aren't going to care how the drinking is or isn't limited. Simple supply & demand economics.