I don’t know if the entire world exists to Storybrooke, though.
They only ever mention Boston:
Emma came from Boston
Katherine was going to Boston
Hansel and Gretle were, supposedly, going to Child Sevices in Boston (why not the State of Maine, Child Services?)
Ruby was going to go to Boston
Ashley was going to Boston
Seems like Boston is the only connection to the outside world that they have….maybe because of Emma, somehow?