It sounds like he has a very warped view on reality, possibly because you have dedicated so long to travelling with him. You're the dutiful wife and your job is essentially to nod your head and smile at his every command.
You have differing views about the children's education for a start. This needs addressing. Or when they turn 13 will you be happier if they boarded?
You have a house in the country and you very rarely visit, I'm guessing due to commitments etc. Do you rent that out to get extra income?
As a compromise I'm guessing you're not all that far from Southend. There must be somewhere within driving distance he can do his sailing. I'm sure in the Olympics they had a lovely sailing place, where the water looked fresh etc.
You need to possibly write an email, not the best form of communication, but you could put it a bit like:
Dear Hubby,
I don't think you've noticed, but the discussions this last weekend have left me feeling pretty unhappy. I have travelled around with you, helping our children settle into a new routine each time, we've just settled here and you wish to move again.
I really love where we are at the moment, I've looked into it, you can do the exact same activities here, without uprooting to Devon or Dorset. My problem is, you mention DC going to boarding school in the week, so I'll essentially be home alone. Such communities are very insular, people being born and bred, with those who move from London being viewed from a comedy perspective, especially those who decide to bring animals into the equation, it's like a full time job in itself. You'll be working, the boys will be at school, I'll be lumped with all the not so glamorous jobs.
I really enjoy life in London, I have friends here, there's so much to do, so many opportunities. The DC are in a fantastic school. If I'm honest I really am happy with how things are, I'm not all that happy that you want to up and move again. I really want some stability, I really want to settle down and make somewhere home. We have the holiday home we rarely visit. I worry that as soon as you get bored of the country life, it'll be something else.
I was just starting to relax now everything has fallen into place, I was considering working. I don't think that many opportunities will be afforded me SW as there would here.
As I said there are many places you can go sailing round here, if you fancy selling the other getaway place and finding one in Devon or Dorset, maybe you can take the DC of a weekend, I can come depending what I have planned. I don't really care how the locals will view us, we lived in a country where security was needed to leave the house, do you honestly think I'm the least bit fussed how others think that we have a second home in the SW. It also affords us to maybe let friends go and stay should they want a break.
I honestly hope you can see where I'm coming from. I know you work very hard and have worked very hard for the family. It just seems like you consider it about what you've done and not the impact it's had on me or the DC.
Maybe in the future we can look to retiring in the SW if that would be a compromise. Right now I really am happy with where we are. I really hope to stay here, look for a job, continue building on the foundations I've laid. If SW is really important to you then a weekend get away could be an option. I honestly don't buy that you're overly bothered what people think, you'll be out sailing and exploring. I don't think they'd be at the front gate with pitchforks ablaze because we choose to spend our weeks in London.
Now I've said what I think, you can consider it and get back to me. Over suggestions that I'll have plenty to do with the upkeep of a place, whilst DC are boarding and you are away. Do you have any idea how isolating that sounds.