You don't have to create all the locations you need before you start playing. You can just as well make them up on the spot, especially for a road trip kind of game. If you've got NPCs that reappear often (someone like Crowley comes to mind), link them to a Theme rather than a location, so you can have them reappear wherever you need them to.
You don't even have to set up aspects for your locations. Give them a rough outline and put up aspects on the fly. Maybe even let your players go nuts with declarations.