Sounds like you'll be taking Interstate 80; I went that way when I moved from N. Idaho to Michigan. You might be able to make it in 2 days between chicago and boise, but they'd be long days. If you're spending the night in the chicago area, you could probably get all the way through Iowa in one day, which would put you around Omaha or Lincoln Nebraska. Maybe even a little further west in Kearney or North Platte. Then there's lots of Wyoming to drive through and it would depend how far you got the day before as to where to stay. There aren't many towns to choose from - Cheyenne, Laramie, Rawlins, Rock Springs and Evanston. There's a really high mountain pass between Cheyenne and Laramie. I didn't see it marked well on my maps and was really surprised when I got there. I was pulling a trailer behind my car and had gone that route because I thought there weren't any passes. It was the 2nd unmarked one I found....
sue- knitting heretic