Thinking space?

Where to get some thinking space?
If, like me, you have a full-time job (teaching, planning, marking, meetings, etc...) and a busy family life (3 loud, boisterous, children), where do you get the thinking space you need to develop your ideas? Move the story along? Come up with clever / sexy / humorous / dramatic repartees? Or just indulge in a little bit of dreaming about your characters and what they might be thinking and feeling?
Driving into work is good for finding thinking space. It takes me about 45 minutes on fairly quiet country roads every morning to get to work, during which I often, but unfortunately not always, come up with at least ONE new idea! In the evening, however, my head is too full of work related stuff to take advantage of the drive home.
I also snatch a little time when I cook the family tea in the evening (I keep a notebook handy next to the cooker, just in case a great line crops up).
The best time, however, is at the week-end. Saturday and Sunday mornings. Early. Even if it rains, as it usually does up here in the North of England.
I leave the noisy household behind...

For one hour, all this is mine. And it usually does the trick.