I cannot give you recommendations on campsites. But, what I can offer is a recommendation about I65. I am in Southeast WI and in July we went to Indianaoplis for a week. We took I65 from near South Bend, IN and I can only tell you they have the worst overpass's in the US, IMHO. It was teeth-jarring every time we got to an overpass. For some reason the state of IN hasn't figured out how to make the highway meet up to the bridges, and every single overpass was a nightmarish adventure. So much so we will take any other route instead of I65 in our future travels. I'd like to see what you think after your trip.
Safe travels and good camping,
Jim & Linda Tator
2013 Crusier CF34SS GMC 3500 8.1L Dually
154 nights in 2013 - 4,370 miles
178 nights in 2014 - 5,082 miles
365 nights in 2015 - 6,040 miles