These remind me of one of Christopher Alexander's design patterns. He said children's rooms should be actually a room with a shared play space in the middle and cubbies built into the walls on the side with curtains for privacy.
"A Pattern Language: Towns, Buildings, Construction" is such a calming book. Makes me feel good reading it, though I realize it's overly utopian and we'll only get bits of it done in the real world.
Many of Alexander's "design patterns" were terrible for actual living on a reasonable budget. Like what are you supposed to do with that space when the children get older? I read the book and was not impressed.
That space takes less than having a room for every child. And the answer to your question is, like with every parent whose child has left home, whatever you want including moving somewhere else.
Maybe we read a different book though. I remember Patterns about properly designing parks and communities, and even some on house design but none of them seemed expensive.
