Unfortunately, I do not think you will find anything close to The Big Windy for your rig. When we went back to our hometown of Geneva (40 miles west of downtown Chicago) we stayed out in Sycamore which is 60 miles into Chicago. You can catch the commuter train from Geneva or Elburn now I think. But your commuting time would kill a one day visit. There are some forest preserves in the area but no sure about big rig availability or hookup situation.
BTW, I have also checked RVParkReviews and RVParky before responding.