We have an above-ground pool about the size of yours and leave it each August/September for about 4 weeks. We don't leave the pump running for the reasons aylad mentioned: too much could go wrong.

We add enough bleach to bring the FC to between 18 and 20 ppm and put on the solar cover. We cut our cover into several sections to make it easier to handle and we leave one of the sections off to allow for outgassing. Only once have we come back to a green pool, all the other years the water was clear and clean.

It's better if you can have someone add bleach now and then but you can leave it on its own. You know how to clean up a green pool—that's a lot easier than to replace a burned out pump.