By the conditions of PG's dilemma, I'm offered the power to choose between two possible worlds, nothing more, nothing less. If I could remove alcoholism without removing casual wine consumption, of course that would be preferable, but this choice isn't on the menu of the thought experiment.

Any world I choose will make some people better off and other people worse off (that's inevitable), but not in equal degrees (fallacy of gray - thinking that all gray is the same color). While making the choice, I don't have a strict deontological prohibition that freedom of any single person must never decrease, all else be damned. If saving one person from extreme harm requires reducing the consumer options of two other persons, I go for it. It's a matter of balance, you have to weigh all the consequences, not just the ones that affect you.

To disagree with my original comment you'd have to believe that a world with alcohol is truly better than a world without. I don't think you believe that. To determine your real opinion, imagine you're given the option of introducing another new addictive substance to the Earth's population. You know in advance that it will spread worldwide, such-and-such percentage of humans will be affected, and such-and-such percentage will lose everything they had and die miserable deaths as a result. To counterbalance that, some other people will have fun using the substance casually. Would you introduce the substance? How is this different from introducing alcohol to a world without it? And how is that different from choosing one possible world over the other?

I do believe that a world where people have the right to choose whether to consume alcohol (or consume drugs) is better than a world where these decisions are made for them.

You're not talking about the whole world, only one aspect of it. Maybe you meant to say "all else equal", but all else is not equal: people are suffering because of alcohol that wouldn't have suffered without it. Are you saying that's unimportant compared with people's freedom to consume wine? Are you unwilling to trade freedom for happiness on principle, no matter how many units of happiness people get for relinquishing one unit of freedom? Or is there a calculation behind your reasoning?

"Are you unwilling to trade freedom for happiness"

For the claim of happiness promised by authoritarian control - I would certainly not be happy to make such a choice.