Great way to think of it! That's not what I was expecting you to say because my own thought was its not just that. Remember, the last time Andy got drunk, his wife ended up murdered, and because his head wasn't clear at the time it happened, it was impossible for him to defend himself against being charged with her murder. He doesn't just want to savor the moment, but drinking for him contains a dire lesson, as I think he feels his drunkenness is what helped land him in prison. Andy is an incredibly smart man who learns fro mother mistakes of others. His loss of control that night of his wife's death taught him something deeply valuable.

That scene also speaks to the audience about his character. We learn multiple times what kind of man Andy is but doing this thing for his friends speaks to his compassion and loyalty to the people he loves. He would've displayed that same loyalty even to the wife who cheated on him, and he learned to show compassion for others from her criticism of him as a cold fish.