I think Oundle benefits from being in a town and having lots of freedom to go into it too.
You can very consciously and unconsciously "step out of your uniform" and so school never feels like prison, I couldn't believe my luck at 13 being able to go into town with friends no teachers and buy ice creams from shops or hang out in a cafe and kick back with friends on a sunday and hang out with a diet coke. Certainly for those from rural scotland/other areas Oundle is probably more fun than being a day student in a school near their homes; much less isolated.
They're also (and am sure other places) so accomodating to parents visiting and allowing you to bring friends out (I was encouraged to bring a friend along for Sunday lunch) that I don't think many found it that difficult tbh.
But I would be surprised at Oundle as it's not that close to their homes and some don't think it posh enough (Im not sure they would care about that personally), but we will all find out in due course...
Hope wherever he (and I hope he gets some say) chooses he has a great time and is well adjusted and the royals become, I know it sounds strange to say, but a bit more boring. Im t ired ofthe scandals of the last 30 years and it's time for some stability. While it's not perfect I don't think the UK being a Republic would be the boon many think it would be.