Fear not, WaG! Alcohol itself won't raise your blood sugar, it's the other stuff in some alcoholic drinks that will cause your bs to rise.
Beers for example usually contain a lot of maltose which can raise bs significantly. Non-diet mixers will raise bs of course and ought to be avoided, but a gin and diet tonic for example should have little or no effect on your bs. Wines will vary, dry reds and whites may produce a slight rise, but over a few hours the net effect will actually be to lower bs readings, as with spirits/diet mixer combos. This is because the alcohol will prevent the liver from producing glucose while it is dealing with the alcohol.
Some people, not naming any names but I'm one of them, use this effect to counter the dawn phenomenon. A couple of glasses of wine in the evening will help me to get a stable bs the following morning.
Bottoms up!
fergus