"We" don't do anything with people - we don't own them. They do whatever they want to do with themselves. Maybe art and crafts. Maybe some meaningless but interesting research. Maybe just live a life of pleasure. I suspect there'd be a lot of different answers. None of them are wrong.
Why do you have to do anything with the people? Certainly they will find something to do themselves, either hobbies like gardening or more serious endeavors like trying to establish a self-sustaining colony on Mars.