Thanks again. We are literally at the stage where we are getting our heads around the idea so we've not looked into any of the fine detail yet. DH is all for the move, thinks it would be amazing for the dc.
Take it from someone who has done it several times, a new country with no international contacts can be very alienating for the mother. It might be great for the kids, but if you are unhappy , lonely and sad, the move won't work. It needs to be amazing for you too.
In an international school, it will be a lot easier for you to make friends. More mothers like you won't be working compare to a local school.
One more thing about the anglo system vs rest of the world, if Russia, is anything like France, Italy, Spain , the teachers will be a lot harsher and no stickers, or positive teaching practises. Forget about the "great effort" sticker on crappy work or the praising praising praising for the sake of praising, because otherwise little Johnny goes homes and complains.
And just to add, we spent 5 years in Barcelona, DD was 5 when we moved, 10 when we left, totally fluent, and now has totally forgotten the language. So your DH's expectations of them maintaining fluency in Russian beyond the stay might need to be adjusted. Unless you actively maintain a language, it goes pfffff in children , teens less so, but are you ready to stay in Russia for 10 years?
I tried a Russian course 10 years ago, it is like Latin, you have declinations, it is very hard and I already speak 7 languages, but hell, was Russian hard. Of course once in the country, it will be easier to do a course.
International schools is the minimum basic of any relocation package. Then the house, flights home, private health, car, driver , security .... are the extras, but school, that's the starting point.
Have you ever been to Russia? Can you go on an exploratory short visit (with covid????) before you decide.
And I second the cold not being in issue, in cold countries, houses, school and buildings are very hot. Kids will leave snowy shoes outside the classroom and be in socks and t-shirt in class, I would have short sleeve top in the office. And the clothes and shoes you find in shops are made for the climate.