To be honest one or two drinks are unlikely to have a dramatic effect spread over an evening.
The issue is that the liver preferentially treats the alcohol before resuming its other function of releasing its glucose stores steadily. This can result in a delayed drop in blood sugar overnight, so one way to get around this is to monitor closely, have bedtime snack and perhaps run a bit higher than usual.
Teh other problem comes in the sugars in soem alcoholic drinks, mixers and cocktails obviously, but also in beers, the darker ones tend too have more unfermented sugars than the lighter ales and lagers. Dry wines end to be lower, but obviously things like port are not. Spirits are pretty much sugar free. So you also need to dose for thesugars, but the general rule of thumb as a starting point is to not dose for the first 10g sugar and then only dose at half your nomal rate to avoid that delayed drop.