Still no opinion, but I was struck by something you said... he doesn't drive because he doesn't have a license? Mine just kept driving anyway WITHOUT a license! I figured this was a common thing for A's to do. I mean, they already take the risk of drinking and driving -- so (they think) who needs a license? They'll just drive anyway. Have you ever heard of this? I thought this was what they did. I don't understand. Is this not a common pattern? Why would they suddenly start obeying the "rules of the road?"
I DO have an opinion. I think you should set boundaries and ground rules while he is sober (which I'm sure you already have, about a million times). I tell my A that I really enjoy doing things with him when he's sober. As soon as he crosses that line, however, I cease enjoying his company. When that line is crossed, I reserve the right to end the activity (i.e., the game) and remove myself from the situation, his company, etc. (As a result, I spend a lot of time alone.) There is no need to "rehash." If he knows your boundaries, he will know why you ended the festivities and went to bed. You don't need to tell him again, and again the next day. He knows. What he needs to learn is that you mean what you say.