We do this; I love it - and therein lies the danger.
I got used to it very quickly, and now I regard my husband as a visitor when he comes 'home'. I began to resent what I saw as his 'intrusion'. I'm about to move to another country, and we've agreed that we'll get a place with an extra bedroom for him to stay when he comes to visit.
This happened very naturally, and also, very amicably, and we're both happy with the situation. We have two children, and they don't know any different, and he's been working away since the first was a baby.
What's changed is that we now live separate lives in a more admitted, conscious way.
We have holidays together, Christmases and birthdays together, and a few other times in between.
It suits us, we're all happy, and certainly much happier than the rocky phase where we were trying to/refusing to admit to ourselves what had happened.
But it's not for everyone. At the moment we both like that we live our own lives, but we're not actually divorced. Not sure whether divorce will happen or not - we have no plans to, but it does seem to be the next natural step, and sometimes I think we're just gradually easing ourselves into it in a gentle way.
I have seen many many many expat families go through this - separation is much more common than one might originally think. It takes a tremendous amount of effort to keep things good in that situation, and to deal with the resentment that will naturally come on both sides.