Well, I also know that Zazen does not end on the cushion, and is all of life ... all the world. I would not drink before or during sitting on the cushion. I do not drink for most of the day, or many days at all. I do not drink when I am working, playing with my daughter, driving the car ... in fact, I rarely drink at all, and never much when I do. All that is "Zazen" too, and opportunities to Practice, in the wider meaning.
But you know, I found myself at Yankee Stadium a few weeks ago, watching the game with a beer in hand. Another day, I was sitting on the porch with a friend, recalling the past, enjoying a glass of wine. That was "Zazen" too, that was life, and an opportunity to Practice in its widest meaning. Sometimes, I sit with "what is" ... and that includes on a sunny day in the bleachers, or an evening on the porch. I was sitting there, one with the moment and just what was. I guess you could say that, in that moment, I was at unbroken oneness with ball game and friend, sun and sunset, glass in hand, the breeze on my cheek ... all being the Reality of the Moment.
Again, just my take of "Zazen never ends" and this Precept. Other peoples' ways that may avoid drinking and Buddhist Practice altogether are good for such people. And for some people to drink at all, especially the addicted, is pure poison.