I wouldn't 3 hours before bedtime injection.... I'm on a similar GHRH & peptide therapy. My fitness goals and alcohol are not really compatible ... but I do have a glass of red wine from time-to-time. I just make sure it is a few hours before I plan to go to bed.
Hard alcohol like vodka, whisky and rum on their own have very little carbohydrate so they should not effect blood sugar much. Alcohol does influence testosterone and other hormones... and since alcohol can affect sleep patterns, it can conceivably affect the release of GH.
My suggestion would be to not use alcohol for the first 6 months of your peptide therapy.... eat clean and exercise. Get GOOD sleep! You're paying for it and going through a lot of trouble with regular injections... you want to realize some results!
Good luck.