Given how those strokes and Alzheimer's all happened in his late seventies and throughout his 80s, I really don't think eliminating his vices will have a huge effect. The man lived about as long as you could reasonably expect someone to live even without those vices. The biggest effect eliminating his drinking is probably going to have is in the image of some of his preferred drinks (cognac in particular got quite a boost in image because of him from what I've heard, rather than being the drink of alcoholic rich assholes it became a smart mans drink).