If you really need to have an alcoholic beverage for a treat to yourself; why not trying to substitute the champagne with something that has no sugar? I think the sugar in it is what is making you crave it.
I would suggest getting a sugar free sparkling water, and adding some vodka to that or a flavoured sparking water that has no sugar/calories if you can try that… pretending? I think that it is the sugar in it that is keeping your cravings going because I haven’t had any alcohol since April (started Keto in February) and didn’t have any until that one night and not since, next time I am having some will be at our October concert. I am just thinking that since you have been having a drink that has sugar in it, that is the problem.
I would either go cold turkey and have no alcohol or the no sugar alternative. To do well with the Keto you have to eliminate the Sugar. Lots of the forum members incorporate some alcohol in their lives, but are choosing some without sugar… the sugar is what is dangerous.
During the times I will pre-plan to have some alcohol I am going to have Vodka with sparkling water or plain water…but still no sugar, as I have been sugar free for ages now and intend to stay that way.