Have you actually spoken to your husband about this seriously? What does he say? What are his reasons for wanting to stay where you are? If his job no longer exists, does he have a new one? Would that dictate things?
Tbh, the location you describe sounds like my idea of hell so I can understand you wanting to leave.
Is it imperative to you both that the children stay in private school?
Do you actually want to stay in your marriage?
If I were you, I'd write down all the things that you're unhappy with and then what you would want those things to look like instead. It's going to be difficult to change it if you don't have a clear idea of alway you want to change it to.
When you've done that, you can work out what you want to change and how to do it.
As an aside, I understand the fear of breaking up a marriage that is no longer working especially when there are children involved but I did it and life has been better.
Even the children spending alternate weekends with their dad meant that I was able to cultivate interes, hobbies and friendships - a life - that was more suited to me.
It's easy to say, "But I can't do that because..." when, actually, you can. I also think its easy to think about the material things that you think will make your life happy - big, beautiful home, private school etc and then realise that those aren't the things that nourish your soul after all.