The most successful people I have seen in GA are single, or divorced. (I did hear a joke recently that said you are not a real charter pilot until you have had your first divorce.)
If you - sorry, your friend - sticks with the Mrs, then she needs to be asked how she feels about holding the fort, essentially a single working mum, while he chases his dream. Even if she goes remote too, then the conversation needs to be had - how does she feel about the Man of the House missing dinner, because he is late back from a charter, or missing the kids birthday party because a last minute charter came up, or never being able to say, yes, honey, I will definitely be there (to pick up the kids from school, to be with the kids while you have a girls night out, etc....).
If she moves too, then you lose the support services of family / friends / neighbours who can pick up kids or lend a hand if the car gets a flat..
And on days off, the fact that as a good partner, you will be expected to step up on the housework / parent front. You either become a very good team, or.....let me give you the name of a good lawyer.