Same here. Mild sleep deprivation usually impairs me much more (and the two things don't seem to add linearly for me -- if I'm already sleep-deprivated, drinking alcohol on top of that won't make things much worse). Then again, I'm about 90 kg (198 lb) and this needn't generalize to smaller people.
My roommate recently sent me a review article that LW might find interesting:
Personal observation says that LWers tend not to drink very much or often. Perhaps that should change, to the degree suggested by the article?
Full article here.