Once I was on an international flight and attempted to order a Cuba Libre, was told they were all out of rum on the flight.
Instead, I asked the FA for Wild Turkey and Coke. She proceeded to bring back a glass of about 8oz of Wild Turkey, and 8oz of Coke. The FA didn't seem to understand I just wanted to substitute out the rum for bourbon, but I was fine with it. It cut down time between refills.