right now, as far as the hosting discussion, EVERY win is critical. I agree that anything less than reaching the championship game would probably leave us not hosting. Of course, before the KY sweep I think hosting was just a pipe dream anyway.
The NCAA is going to put one regional up in Big 10 country, no matter how much they might falter or have their RPI drop. And if it did drop too far, they'd just give another Northern team a host site.