My father consumed about as much as me but had lots of spirits hanging around the house while I grew up. I never touched them as they smelled foul (as they do to a young lad).
My mother barely drank anything. As to their tolerances, I couldn't say as I never saw either drunk.
My father's brother did drink himself to death, or so I'm told. Is that really a valid way of dying?
Well it's not a bad trait to have, it is a poison after all.
I've always thought Nicholas Cage's character in Leaving Las Vegas is one of the most tragic characters out there, so drinking yourself to death, not the greatest way to go!