In Summer, 2017 I spent a couple of nights at the McCormick Place truck marshaling yard in our 2016 Jayco Greyhawk.
I found out about it on this blog:
https://www.gonewiththewynns.com/dow...ago-rv-camping
It worked out great for me and my two kids (ages 7,8) while we were traveling back to Montana from Maine.
It may not be to your level of comfort, but I wouldn't hesitate to stay there again.
Safe travels,
Doug