Rental car Bayport with return to IAH

We plan to spend 3 days in Houston after we return on Sunday from our cruise. I've been reading about various car rental options. Anyone rented a car in or near the Cruise Terminal and returned it to IAH upon departure. I thought it would be more cost effective to find a rental agency in the vicinity use the car to drive to our Airport area hotel then drop it off at the airport or another rental location in the area that has a shuttle to the airport. By the time you add the cost of getting from the terminal into to central or north Houston then add a car rental it gets pretty pricey. Any other good ideas?

If you are sailing out of the bayport cruise terminal the only one that has been reported in the area is Enterprise, but they are closed on Sunday.