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.
The company we use claims 80 hours. However, it depends on metabolism and the amount of alcohol consumed. If the person drank enough to bring their BAC to .08 on a Friday night, it will show up if I test them Monday and sometimes Tuesday. I have an Operation Golden Flow sometimes. Usually the Monday after a big holiday or the super bowl.