Ahem..not Clinton.

. I would suggest a stay in the Quad Cities. Not far away. LeClaire is a small town with a couple of newer hotels that rank good on trip advisor. They are very near the river road which you can take to Clinton and I-80 which you can take everywhere else. Davenport is where a person would find all the big stores/mall/theaters.
LeClaire is home to American Pickers. The shop is open quite a bit to tourist. It is smaller than it looks on tv. Then, you can walk and shop the small stores on main street.
Across I-74 bridge in Illinois is the John Deere museum. Good for seeing the big equipment upclose. Not sure how thrilling this would be for girls.
Have you thought about going toward Chicago? If your daughters aren't too old for the American Girl museum...it's a popular place to go. Chicago is 3+ hours away.
3+ hours to Minneapolis. 4 hours to Milwaukee.