Within the local galactic cluster there would be no way to travel intergalactically since no power source, including nuclear, would last the several million years needed to make the trip. We might populate the Milky Way were it not for Congress, but we wouldn't ever go beyond the Milky Way.Unless we learn how to tap into dark energy! (Assuming the density of dark energy is high enough in between galaxies.)
Well, FTL and time travel and all that would be great, but at the moment we have to go with what we know how to do. Think about it, if we knew FTL were possible because we saw somebody doing it, would we not immediately do research to see how it is done? Just knowing somebody is doing it would be a valuable knowledge.