Dear Ripper, just a word of caution about ultimatums. Don't set boundaries you're not 100% prepared to keep. The A is masterful at pushing boundaries, and learns not to respect them when they get their way. If you say you won't live with someone who is actively drinking, and he then drinks...what are you prepared to do? Make sure you take the time to think things through.
Are you going to AlAnon? Find a meeting near you, and give it a try. It's suggested you go to 6 meetings (can go to different ones) before deciding if you like it or not. The meetings are a great place to get support, to hear how others got through, and to formulate a plan for your own life.