Have you tried Enterprise Rentacar?
https://www.enterprise.com/
You may want to try driving it to Miami and then dropping it off at Enterprise or having them come and pick it up at your hotel or location before your cruise. Then, have it set up to rent another one for the drive back. If this is possible, it might work.
I have recently used this company locally, and they are very customer friendly, and I know they have services where they bring you the car, etc. So maybe a phone call to them locally will help find a solution.
$ 2K is high.