Hi Wayne & Kara,
We did that 2 years ago - Beautiful Trip!
We started in Sault Ste Marie and went west. Koa in Wawa was ok. Koa in Thunder Bay was good. Lakehead Basin Marina in Duluth is a good place to stay. Ashland City , Wi has a great city park right on the water - big sites.
From Grand Portage south to Duluth there is a ton of stuff to see! You are right on Lake Superior the whole way.
For some more in depth info on places to stay refer to Big Rigs Best Bets.
Jamie