It should be a cool trip. There are many before you who travelled and vacationed via English 3-speeds. For many years around the world, the three-speed was considered deluxe bicycle travel.

With just a bit of internet searching, you can find many great adventures written by people who did just that especially throughout Europe.

I rode a three speed around the perimeter of Chiba province in Japan. It took me about five days. The bike was way to small for me, so it was a chore, to be honest.

I think for you, the challenge will be the hills because you will be travelling in glacial till country. The final climb to Duluth should make you a hero or kill you or both.