The San Diego Quilt Show is held in the Convention Center, down town San Diego. There is public transportation so you don't have to stay next to it. It is Also right next to PetCo Park, so if you are lucky and like baseball, you may be able to take in a game.
You just missed the Road to California Show which is held in January - that is the largest quilt show in Southern California - it is held in Ontario, CA. I love that show - it is like the 3rd week in January.