If the OP puts 700 miles on a rental car rented for just 24:hours, I would be a little concerned that Hertz would be unhappy with him. Rental-car companies have been known to put renters on the DNR list for "excessive" mileage on an unlimited-mileage rental.
I don't know that it's ever happened after a single, one-day rental, but I would suggest looking into this a little bit if the ability to continue to rent from Hertz is important to the OP.