Hermags
re your comments in quote marks (my responses are underneath):-
"Thanks for your replies. To be clear - he does come home after a night drinking (sometime in the early hours) but stays in bed or on the sofa until the next afternoon while I take the kids out".
If your children do not already notice that their dad is absent again due to drink they soon will do and they will also pick up on any unspoken reactions from you re their dad also. You're the one who takes them out in such circumstances, to me it seems that you are making the best here of what is really a bad job. You are in some respects trying to soften the blows for them. You cannot fully protect them from all this though.
"I do think about the role models think - I think both him and his brother get their drinking habits from their Dad (who actually treats their Mum appallingly, in my opinion) and I do worry about my son in particular getting caught up in the same mentality. But when he's on form he is great with them - and they adore him".
As for this "well the children adore him" I would take issue with that. They may well on some level be terrified of him, they certainly see how you as their mother are treated by him. It is not a reason for you to remain in a poor relationship. Your children are still very young and they are indiscriminate in their affections for their dad. However, your H comes from a family that is at heart not emotionally healthy. We learn about relationships first and foremost from our parents, what did his parents teach him?. A shedload of damaging lessons that is what and his binge drinking is an overall part of that. Your worry about your own son (and other child for that matter) being caught up in that mentality is a valid one.
"In terms of what I get out of the relationship - he's good company, he makes me laugh a lot, we have things in common, he mostly listens when I talk about work etc".
So nothing there about you loving him, trusting him implicitly or meeting your emotional needs. These are really the barest of minimums for a relationship in any case. Your reply to this re what you get from this is not that reassuring to be honest. When is he actually good company, only when he is completely sober?. He has not been much company to his children and only replies that he is going to try harder. Its not much is it and he also has not explained how he is going to achieve this aim, he's just paid lip service to the problem to shut you up (for now).
Has the frequency also of his drinking episodes increased over the last 12 months?
"I guess the biggest question is whether I still love him - and I guess the honest answer is I really don't know. Hoping counselling might help me with that..."
I think it will help clarify some things further in your own mind. I would think that talking to Al-anon could also help you now too. You are affected by another person's drinking.
Alcohol is really a cruel mistress.