Academic job in country B, family in country A. Impact on work/life balance
What a massive decision you have to face and I don't envy the decision you have to make.

I don't think there is any magic formula for this and comparing the situations of other couples is a moot point; it's comparing apples and oranges. If you both believe its the best thing for you to take this job then there's no reason why you can't make this work, in the short term.

Have you discussed what the plan is further down the road? Would there be any suggestion of your family moving to country B when the children get to the end of their primary education and are starting secondary school? At roughly 10 years old, they're still very much young enough to make the move without worrying about them making new friends and learning the language (if that's an issue), kids are very adaptable in these situations.

Beyond just your family, what about you? You'll be alone in a new country with your family over a thousand miles away? Skype and regular messaging may seem like it'll help but at the end of the day, and I don't mean to bum you out, you will be on your own the majority of the time.

I hope it works out for you regardless of your decision!