So far since we started AS&SH, everything has been Hyperborea (except for a brief foray to a space-pixie space station). It's the world. I have heard it referred to as a "small sandbox"--maybe I just have limited horizons, but to me it seems huge. Our campaigns have always tended to stay pretty local, so I already feel like there are just huge segments of Hyperborea I'd like to get to but don't know how it will happen. There's already been one teleportation, though, and the players seem fine with where they are and under no real urgency to get back to Brigands Bay.
Which is maybe partly my fault. Keeping adventurers hungry to me has often meant that at least for a while they don't have a secure base--until they can take it and keep it or make themselves useful enough that someone will be waiting for them to return. Like Conan before he was king--just keep moving to the next adventure.
That said, I intend to have some portals to other places crop up, especially Yuin-Soon and, unless I place it in Hyperborea, A Red and Pleaant Land.