Easily months even with an airship, if they can appear anywhere in the world or with a delay. I can think of a few locations that would be particularly promising, but they'll be difficult to reach without assistance.

[Forward, then left, then there's a few more rotting bridges to cross. Without prompting, Rosie aims an Ice Beam at a green gator tail that was approaching in a most suspicious manner.]

If no wormhole can be found on this planet... I can attempt to open a Torsion. But that will make things worse for everyone involved, so it'd be best to avoid that.