I think the answer is always related to better tailgating. My family lives in Iowa City, and I go back to tailgate with my friends for a game at least once a year ... even as a non-Iowa fan, it's just a damn good time! And guess what? We literally never go to the game, we just go downtown to a bar as soon as it starts. However, we would never miss tailgating by the stadium (i.e., we would never just head straight to the bars), and inevitably some people end up going in because we are right there.
Grange Grove and other areas like that need to be must-attend locations. If they are, the atmosphere around the stadium will be so fun that at least a few people who otherwise would not attend will trickle into Memorial Stadium. This is all boiling down to the same basic point, though - get people NEAR Memorial Stadium and have that location be so fun you wouldn't want to miss out on it. If we get good at football and continue to build a tradition of tailgating, the potential is absolutely there (for God's sake, Indiana has been known as a great tailgating destination for YEARS...). I mean, these pictures LOOK like a great tailgating atmosphere, we just need consistency and time to build up the tradition of it:
The only thing stopping Grange Grove from becoming similar to THE Grove is it hasn't gained the reputation of being an epic party yet. Sorry to derail the thread, but there are few things I am more passionate about than Illinois improving its tailgating atmosphere, because the potential with the given spaces is so great!