If you have ever seen the movie Wall-E it shows this possible lifestyle, yet the dramatic results. Humans would not be able to go outside and exercise due to the atmospheric pressure. Therefore, we would all end up fat, have lack of vitamin D, and nutrients.
Though finding another galaxy with a planet similar to ours is a possibility but by the time it would take to travel to this so said galaxy it would take years meaning your great great great grandchildren would only be able to get there, or if you traveled at the speed of light, but then it would be that planet's future (because when you travel at the speed of light, you feel you are moving at a normal pace, but the world is moving faster below, so its like time travel)
hope this helped. -- but hey I hear Mars has water on it nower days.