When the Bears announced they were coming, people initially thought Bears fans would be taking vacations to Kankakee County for camp...three days to a week, hotels raking in cash, the State Park Campground being jammed full. It did not end up that way.
They probably got more total people, but mostly on day trips. It's only an hour from the loop to Olivet. The hotels, as a result, never got the great windfall they thought might come. Gas stations usually had people filling up before going home on cheaper/lower taxed gas and getting a fresh beverage/snack, so they saw a jump in business. Restaurants were getting lunch or dinner before or after practice, but the one meal was generally it - because fans were not generally staying overnight causing a couple lunches and dinners.
And yes, there were "groupies" looking to hang out in the bars trying to see players. But there were also bars which were willing to cater to the Bears and let them, say, use the "party room" without fans. I really think it would have been a wildly different situation if, say, the '80s Bears were in Bourbonnais...I could picture the punky QB shotgunning brews with McMichael and Hampton up and down Broadway in Bradley...