My 13 yr old has lived in 6 houses, 11 year old 5, 6 year old only 2.
Moved to the North to be nearer family. Lived in rented to give birth to Ds2 very near family looking after high needs Ds1 whilst i was hospitalised. Moved North Wales, divorced as XH couldn't cope so needed to sell dream house with baby and toddler, oh the joys.
Shockingly met and moved in with DH2 within three months of meeting, sold his small house 3months later in parallel with buying new dream home family house. Married six months after meeting, had DD just over a year later, major series of life changing events ment we needed to move - devestated, moved. Now a few years on, actually quite settled back very close to family and DS1 in fab special school, DS2 in an associated very good secondary (just started), DD in an okay primary - but all oversubscribed so best we can probably get.
I found moving schools etc when they were little was okay but the older they get the harder it gets. It would be very very difficult and quite damaging to uproot DS1 now he's yr 9 and settled. A move at this stage would really impact him. Ds2 is 11 just yr 7. He'd cope with a move durring this year but I think beyond initial secondary year it really would start to have an effect on results, friendship groups and his fragile confidence.
We are survivers though as a species. If needs must, then you do what you need to and make the best of it.