Quite plausible actually, not just in principle.  In the inertial frame X of some planet in a galaxy 27 billion light years from here (distance measured in frame X), the universe is currently (simultaneous with us now) about 30 billion years old.    Yes, the universe for such an observer would be quite different from what we see here since for one thing it appears to be over twice as old. Much more mature galaxies and such. Yes, we do know of galaxies moving at sufficient speed