I do agree that H will have to come to the realization that if work is more important to him, then he'll find himself alone very soon so he can devote all his time to his beloved work.
I am a firm believer in his attitude toward work filling a void he has inside that affects his self-esteem. Once he can pin-point why he feels he needs work to be complete, he'll be able to leave work for what is really important - you and his children.
However, he may not get to that in time to rescue your M. That would be the real tragedy, but he is the one choosing to walk this path.
Hopefully for everyone, your H's IC sessions will allow him to see this before it is too late.
