"In any ChurchilL lexicon, 'A' is for Alcohol, thanks to WSC’s audacious assiduous fanning of of his reputation for his capacity, though only once (after a bout of toasts at the Tehran conference) did anyone testify to seeing him the worse for drink."
The above quote from: Churchill: in his own works. Edited by Richard M. Langworth.
There’s no recorded evidence, that I know of, of Churchill having alcohol problems. There’s lots of popular stories, but no reputable historical evidence that he was anything more than a regular health consumer of alcohol.
In his own words: “I had been brought up and trained to have the utmost contempt for people who got drunk—except on very exceptional occasions and a few anniversaries…”
The extent to which Churchill drank is exaggerated in the popular imagination, he may have been alcohol dependent, but there's no contemporary accounts of him binge drinking. It's likely that he was what we would now call a high functioning alcoholic, drinking just enough to satisfy his addiction throughout the day but not becoming noticeably intoxicated.