Like hypoxia, flying only slightly drunk should be a sim training exercise.
There is a film somewhere of an exercise exactly like that. The crew of, I think, a 727 were put in the sim and gradually fed more drinks. It should be compulsory viewing. If I can find it I'll post, but it was many years ago.
Edit. I can't find the film, but here is a medical article about it.
https://www.ncbi.nlm.nih.gov/pubmed/2012569