Boundaries are for us, not for them. You can tell him, "If you've been drinking, stay away from us," but he is under no obligation to comply with your boundary, and it is likely to cause an argument or some other form of drama. So if you don't want to be around him when he is drinking, then you need to find a way to not be around him when he is drinking. Which...from your story, sounds like all the time. I am sorry.
Our A's get frustrated when we start changing. It makes them very uncomfortable when the status quo is disrupted.
Boundaries were tough to wrap my head around at first. It's important to understand that they are in no way effective tools for controlling the addict's behavior, only for defining what we can and cannot live with -- and making decisions based upon that, not whatever the A is doing.
Sending you strength and patience -- sounds like you will especially need the patience!