The question one has to ask is if you have a Nyquil or a beer and your not going to carry because of that tiny amount in your system (depending on how well you handle it) What happens if something does happen where you would actually need to use your firearm.
2 questions really
Would you rather be potentially dead or in a hospital somewhere clinging to life?
or
Would you rather be court trying to explain yourself, since you probably shot under the right circumstances, where you’d probably get away with only being charged for the drinking and shooting part?
Personally I don’t drink, and never will. I'm 19 so I cant legally anyways, but when I was in Germany I tried some and didn’t like it. But if I was the type to drink or go to bars I would carry.
I'd rather be judged by 12 than carried by 6. Good motto in my book.