Would it really only take 4 weeks?

It is quite obvious from the film the main character's problem with alcohol had destroyed most of his life before he decided to 'cash out' and move to Vegas and drink himself to death. It is apparent from the film that the main character had everything going for him-good job, house, family etc. The boss who fires him is close to tears because he recognizes what alcoholism has done to Ben's life. Ben had attributed his wanting to drink himself to death to the fact his wife had left him with his kid, when it fact it was the alcohol which caused it all along. Alcoholism is slowly progressive in its destruction- it hit Ben hard. He couldn't go back. Ben is obviously a hopeless romantic who had a problem with the booze, and when his wife left him he was shattered. Sera represented the way Ben was and what a person he was and all that.

I'm not an expert, but I believe it could take significantly less time to drink yourself to death if you just went for full-out alcohol poisoning. It would be kind of like an intentional heroin overdose. But Ben seems to want to do some kind of sustained, coherent drunkenness until he gets to the end. Kinda sorta enjoy himself, if you can look at it that way. His body is also used to a certain level of alcohol so it might be harder to OD quickly. Actually, withdrawal for an alcoholic of that level can also be life threatening--you see that when he needs to guzzle his "screwdriver" to stop his shakes. I have some small experience with this and it really is shocking to see what alcohol addiction can do--and I mean just the physical part, not even talking about the emotional devastation, which is only hinted at in this film.

I saw a documentary about a girl who was one binge away from death, a guy who was about to die from liver failure years after his last drink and a young man who had turned custard yellow but was still drinking heavily - I think you could live from a few minutes to years - I bet it isn't unrealistic in the film though.