The relationship between alcohol use and cognitive function appears to be nonlinear, and indeed non-monotonic: light drinkers have better cognitive performance than nondrinkers. Reduction in cognitive performance for heavy drinkers is measured more in men than in women.

Source: Rodgers et al (2005), "Non-linear relationships between cognitive function and alcohol consumption in young, middle-aged and older adults: the PATH Through Life Project" — http://www.ncbi.nlm.nih.gov/pubmed/16128717

Chronic alcoholics do not have reduced numbers of neocortical neurons, but do have reductions in white matter volume.

Source: Jensen and Pakkenberg, "Do alcoholics drink their neurons away?" — http://www.sciencedirect.com/science/article/pii/014067369392185V

Neither of these studies speaks about the specific measurement you're asking for, IQ, but they do address the general topic.

(Chronic alcoholism is also associated with specific neurological conditions such as Wernicke-Korsakoff syndrome, which is caused by thiamine deficiency — someone who's getting most of their calories from booze is not getting enough nutrition.)

I did a few Medline searches some time ago and the answer appeared to be no. Since then I've done enough self quantification (mostly with Anki) to know that sleepless nights and even slight hangovers severely damage my abilities for several days. I was unaware of this effect before measuring my performance. Even small amounts of alcohol damage my sleep, and you could probably find studies that conform to this observation. This knowledge slowly creeped on me to seem actionable enough that further searching for studies felt like a desperate attempt to rationalize self sabotage.

Measure your performance. Temporary effects are not a direct answer to your question, but might be sufficient knowledge for decision making.