Go with what your provider tells you.
This forum has been invaluable for me and I have learned so much, however it has also taught Ne that every surgeon and provider have different rules, and we shouldn't poo poo anyone surgeon, providing they are reputable. My surgeon, Ameet Patrl has outstanding stats and not only will allow you to drink pre op, he has just told me at my 6 week check that I can now have a little drink just 6 weeks after.
We all have to be careful and make the right choices, but I really don't think a couple of drinks are going hurt you, my surgeon has never had to cancel an op due to enlarged liver and he doesn't require a pre op diet.
Good luck with your op and your choices xx