only going from experience, in chicago not even the police want to enforce the bullshit law of being 15 feet of a doorway. for the most part.
some bars and other places get uptight if you are too close, this is probably more for the reason of not having their entrance littered with cigarette butts
2 years in i don't mind the smoking ban TOO much, just sucks having to go outside during the winter but yeah, whatever.
it'll probably be the standard in the US within the next decade or so