N.M.
He's a functioning alcoholic. It's better than a "falling down drunk" alcoholic in some ways, but it's harder to convince a functioning alcoholic that that he IS an alcoholic. He'll say, "Look, I go to work. I do what I have to do. My drinking is not a problem!"
But if he would rather drink than spend time with his kids, then his drinking is a problem. It's ruining his family relationships and it's affecting his marriage.
You need to sit down with him and talk about this (when he's not drinking, if possible). He will get mad. But don't be afraid of his anger. Men can use their anger to manipulate women, to.bow us into agreement. As long as he is not a violent man (he doesn't sound abusive or violent to me), you need to confront him and let him know how much his drinking is affecting the entire family. Maybe he never thought about it that way before.
If you are nervous, or if you do think he may get violent, have a friend of his, a relative, or religious leader there with you. He needs to know this is serious and things must change. He must seek help.
Ask him to try, for the sake the family. If you approach him positively, without being too accusatory, and if he is a good man, hopefully he will be receptive.
I wish you the best. http://keystosimpleliving.com/relationships_marriage.php