Do you have any sort of status with Hertz? For a rental of that length, with spending as much money as you are, please make sure that you'll be getting some sort of miles or points.

If you have status and reserve the Expedition, you'll get at least that, possibly more. I got an Expedition when I reserved a mid-size in RNO back in Jan (as a 5*), but it was just a 1-day reservation. It had 3 rows of seats, with the rear heat-a/c unit. It was very comfortable, but the gas mileage wasn't the best....