You didn't say where in IL. We're in western Chicago burbs and go back to Ithaca NY to see grandkids every year. Take I 90/80 to 480 at Cleveland to I271 back to I 90 in OH. Driving at 62mph, we stop at Erie KOA after about 8 hours drive time which includes fuel stops, food, etc.
Wife has had it at 8 hours on the road, no longer likes those 500+ miles per day
That puts us about an hour +/- from Buffalo and Niagara Falls.
Be sure to have or get an I-Pas, saves time and $$$$$.
Coming back home, drop down to PA turnpike to get to Gettysburg are and western Maryland for Antietam battlefield.
If you need an overnight stop in OH, the turnpike has RV spots at MM75 & 238. $20 a night.
