John, I see two issues here:
1. Legal
2. Spiritual/moral
1. Depending upon the individual a "buzz" may or may not meet the legal blood-alcohol level that exceeds the limit and thus becomes a misdemeanor/felony depending upon the state.
2. A "buzz" inarguably means you are "impaired" and thus one's speech and/or actions will be less/not under one's typical control. Scripture is more than clear that nothing should supersede the control of the Spirit and thus visually a professing Christian is compromised and not glorifying God nor displaying a positive witness to others.
IMO, regardless of these two perspectives, driving a vehicle when "buzzed" is definitely not recommended.

PS. There are other Reformed individuals who don't drink besides yourself. An occasional glass wine of wine or a beer in my view does not make one a "drinker". Abstinence is not taught in Scripture but moderation and control are.

Some churches still serve wine at the Lord's Table and if one insists in abstaining from all alcohol for whatever reason, then not attending the Supper would be far worse than drinking 1 oz. of Beaujolais or Port.
