Some encounters may take longer than their allotted times, while others may take less than the time allowed. It is NOT necessary to use the allotted time for any particular encounter if you are coding based on the documentation of the three key components. In other words you are not penalized for being efficient.
If you are only going to have 1-2 drinks, you should be fine to breastfeed. If you are going to binge drink, then you should wait two hours per drink before breastfeeding. Once the alcohol is out of your blood it is out of your milk. And pumping & dumping does nothing to speed this process up.
If you are drinking on an empty stomach it will hit you faster than if you have just eaten (fatty foods slow the absorbstion of alcohol). So, depending upon all that, and what type of drink you are having and how fast you are drinking, it could be 10/15 minutes and up