All the best to you on your journey! There is a way to avoid Chicago, however I don't know if the savings in mileage would cover the cost. There is a ferry across lake Michigan. Its starts up on the 11th. Though You could possibly be done the whole journey by then 500/mile per day.
https://www.ssbadger.com/
The journey is basically a 2 day process. It will be completed before the ferry runs unless of course i run out of fuel somewhere along the path.