two words: don't go.
people do not work on their marriages over the course of a weekend, especially if one of them has untreated alcoholism but promises not to drink for about 72 hours. he wants to be in charge, FORCE you to do something with him so that he WINS. that you think you have to breathalyze him FIRST really says it all...........
again, don't go. it's a farce, a smokescreen.