Want a new world with 20x15 lots - like another Magnolia Promenade

I think that a couple new blank worlds with different themes would be great so we could pretend to be in different time periods (like futuristic or medieval or Victorian/steam punk, etc.) or locations (Alaskan wilderness, deserted island, jungle village, Wild West) without actually having to have an entire pack made (unless they wanted to, of course).