I think, OP, you are being unwittingly and unnecessarily swayed by Winchester's reputation which could prove detrimental to your son's education in the long run. You talked about Oxbridge, distance from school, manning up, etc in your various postings. But I hear precious little of what your son really wants or what you want for your son in the future besides your Oxbridge aspiration. Indeed, Winchester was a big deal of yesteryear but circumstances have changed beyond recognition in the modern day.
Even state schools today are giving the big-name public schools a run for their money as far as Oxbridge goes! For example, in my part of north London here, it is not a big deal now to see the local grammar schools sending dozens and dozens of kids to Oxbridge each and every year. Queen Elizabeth's Boys (Barnet) send more than 30 kids to Oxbridge yearly on average; and the girls' school, Henrietta Barnett is not far behind. The same as Latymer's in Enfield, north London. Do I hear these schools boasting as being "very academic"? Not a word!
This Sunday Times League Table from a couple of years back (the latest that I have) will tell you the true state of affairs as far as academic school goes. You'll soon discover Winchester's "bone" isn't as big and juicy as you might have thought, compared with Alleyn's. But for the full fee-paying parent, we are talking about doubling the fee for that little insignificant extra.
What I personally look for in a school is their alumni's final destination - not Oxbridge - i.e. who has this individual become in society. It's no good to me being highly academic and intellectual with a First from Oxbridge; able to appreciate to the finest details Bach's and Mozart's obscure Movements but living like a hermit in your own world. It's as if you can live on air and water alone (perhaps with some apples from the garden)? And you pay a quarter of a million £'s school fees to have this privilege? 🤔