1-2 drinks every night (which is not what the author said they were doing there) can be anywhere from not a problem at all to high-functioning alcoholic. I think the simplest way to tell where on the gradient someone is is how they handle a night where they don't get a chance to have a drink. Is it something that's not remotely a problem and they wouldn't even realize it was the first night in a while they hadn't had a drink? Is it something that bothers them but they'll deal with it? Is the idea unthinkable and they always have alcohol on them so that they can sneak a sip even in circumstances where it's inappropriate?