It'll be interest to see if/what effect the eventual addition of the hockey program has on their fan base. For Penn State, it gave them a winter sport to care about. Of course, Illinois used to be consistently good in basketball (and maybe this year they'll finally get back to the top half of the league and make the tournament).
I've never been to Champaign, but I've met enough Illinois grads, especially from when I lived in Chicago, to get that they look at their football program as a lost cause at this point, at least for now. Of course, the Purdue fans I met 3 years ago kind of felt the same way back then, and their situation wasn't that different, so I think it could just take the right coaching hire.
Iowa State, Washington State, Kansas State, Kentucky, Baylor, Duke, Mississippi State, California, Wake Forest, and of course Northwestern have all had more success in recent years with similar or worse support, while other programs with more advantages have underachieved as much or moreso (eg. Tennessee, Nebraska, UCLA, Arkansas, Maryland).