On the afternoon of August 4, 2005, I flew to O'Hare Airport in Chicago, and rented a car.
I drove straight to the trailhead for Timms Hill, WI, reaching it that evening. After visiting the highpoint (and climbing the tower), I drove northward and camped in northern WI. The next morning (August 5, 2005), I drove to the trailhead for Mount Arvon, MI. After hiking to the highpoint, I drove to the trailhead for Eagle Mountain, MN. I hiked to the summit of Eagle Mountain (less than 24 hours after landing in Chicago), and then drove south of Duluth, taking a hotel for the night. The following day (August 6) I visited Hawkeye Point and the next day I visited Charles Mound on the open date, finishing up the Lower 48 HPs.
If you don't mind driving a bunch, and if you have your route planned out, you shouldn't have any trouble at all.