A follow-up...

ColinsMum: Scotland is a possibility, though (due to work reasons), probably only near Edinburgh or Glasgow. Would that be close to where your son's school is? (Feel free to let me know via PM!)

Dbat: The Carpe-Diem schools look intriguing. However, they appear to be 6-12 grade, so not as relevant to us just yet. Maybe we'll revisit in 6 or so years.