Another member and I were discussing this today. He mentioned that if he were unable to buy another bottle, he'd be fine for 10 years. I estimate I'm not in as good a shape. So the question can be looked at from several perspectives. A new prohibition is passed OR distilleries start being able to sell everything they make overseas at 10X price so they do not bother selling domestically or whatever. Regardless you can't buy (or can't afford to buy) any more alcohol as of this afternoon.
Yes, I know, if we knew this was coming we'd all stock up and if it happened moonshining would supplement some stocks and you could find Wild Turkey on ebay for $1000 a bottle but.... the question is straight up. Based on your consumption (or your modified consumption) how long would what you have today last you??
At my usual rate I'd be good for 1 1/2 years. BUT if I knew I had no more Bourbon (or anything else) coming in I would likely slow down and that would extend it to 4 or more years.