I would imagine the best way to survive in this galaxy is to build self-sufficient mobile Space Stations that can travel from star to star and move into any orbit of any planet. Every Star is doomed it is only a matter of time before it exhaust its matter. It would only make sense that you would want to be able to move your civilization when the threat appears. Because if you cannot, your civilization dies with your planet. Hence existing in space; living on your getaway vehicle.