I mean, honestly I'm not so sure what the huge rush is to expand to another planet when we're having so much trouble with just one.
It's not that I don't want to see us move past the boundaries of this planet, but on the list of things I'd want to see before my time is up on this planet, there's plenty of things like the end of world hunger or bringing the poorest people in the world to an infinitely better standard of living that come way before us living on another planet.
In the very long term moving to another planet is a way to stave off the end of our species (amongst other positive things), but in the very very long term the odds are we won't live on indefinitely, I think improving the lives of those who come before now and that time is probably the most worthwhile thing we can do.