any suggestions on a northern Indiana vacation?

Hello, I'm wanting to take a short vacation and we're considering running up to northern Indiana. maybe the first day check out the Duesenberg and football museums in South Bend, then perhaps Notre Dame and the river walk, then the next day head over to the dunes national beach, then maybe on to Chicago.

Is there anything I need to catch in that part of the state?

is 1 day in South Bend enough?

Is 1 day enough for the Dunes National lakeshore?

How is the swimming there in July/August

Are there any neat boat tours out on the water?

Would Lake Erie be a better lake to visit?

any other suggestions?

thanks

Steven