Safeandsound...
I read your post several times and keyed in on the part that your husband is receptive to couples counselling..
I am not a counsellor. I just know I have been married 26 years to a wonderful woman who has seen me drink too much black out and pass out.
She made it quite clear she was getting tired of seeing her husband like this. She makes me want to be a better person. You are quite correct once that first drink is taken all bets are off.
It is really positive your husband is willing to go to counselling with you. I wish you the best.