They wouldn't need habitable planets at all Escaping one solar system with some amount of colonists is probably harder than developing the technology to not ne

They wouldn't need habitable planets at all Escaping one solar system with some amount of colonists is probably harder than developing the technology to not need whatever counts as "habitable planet" at the other end. They'd use the new system's ressources for all sorts of things, least of which would be biological survival.