You could go up I55 to I80 at joliet Il then E on I80. Then take I80 to I94 then take exit 40A US20 that becomes In2 to US33 toward Goshen. This is the best major route from the South and West to miss most of Chicago traffic and there are no tolls on this route and the roads are good.
We haven't been that way ourselves, but DH looked at map and says it's a decent 4 lane road. If you're not in a hurry, going through those small towns is fun! Makes me think of what America should be!
Well, he finally looked closer and 24 is 2-lane. So we may go around Indianapolis and catch 31 to 6 to 15.