I understand everyone's concerns about taking all the survivors to Bolder. But if they had multiple colonies, wouldn't they still be facing the same problems? If you have more colonies to protect, then you need to use more soldiers to protect civilians. After all, no area is completely safe from zombies. And if you have so many soldiers protecting the colonies, how many would be left to gather information, rescue survivors, or destroy zombies. Plus, you'd have multiple planes flying to different locations, which means more fuel will be wasted. So to me, it makes sense for them to stay in one place until the zombie threat is dealt with.