Hi Dragonfly Sky,
Oh my gosh can I relate to your story. I live in a small community. I'm not happy there, want to move, but don't know where. I have become involved with a poly family (on this board), about 6 hours from me. I can also understand the circumstances of being the one who's single with more flexibility and more time, so needing to be the one who fits in.
I don't have that much in the way of advice at this point in time because I'm still questioning things myself.
A few things. I can understand why the guy you met didn't mention polyamory right away. Were you just including this as part of your story? Or did this bother you?
I want to second what Ciel said:
If you do it based on being closer to him this early in the relationship then if the relationship doesn't work out then you are up a creek without a paddle, and full of resentment of what you gave up for the sake of the failed relationship. So if you can find a job and a place ot live that is an improvement in your life, and if it happens to be a lot closer to them, then great! If things fall through you have still made a good move for yourself.
I'd start by asking questions like - why do you want to be in this particular relationship? If the relationship wasn't a factor, where would you like to live? I would also talk to him/them about your concerns. You might have a better understanding of how/if you fit in if you understand more where they're coming from. What are they open to exploring?
Do they only want to be primary with each other? Are they interested in making others "equal", so to speak? How does this sit with you?
Does polyamory ring true for you at all? Would there maybe be an opening for you to explore a deeper, more primary connection with someone else that would balance out the dynamic you have with this couple? Just a thought...
Hope some of that helps... (actually it helped me, so thanks!)