Before I quit drinking I took plenty of benzos with plenty of alcohol. If you don't have a tolerance to xanax or alcohol and you take that 1 mg then binge out on 5 shots you might find yourself passed out. Even though it's not recommended I've known many people taking benzos who also drank heavily. If you're used to that dose of xanax and used to however much vodka you end up drinking then you should just be chilled out. The two combined will simply have an additive effect.
Being responsible, I have mention the all too familiar warning that an overdose of benzos combined with excessive alcohol consumption can be fatal. But with 1 mg of xanax to calm you down for a car ride followed by a drink or two I think that the worst that would happen to you is a blackout. But even that I have only known to happen to very small people, who are inexperienced with either substance, taking a lot of benzos and drinking a lot at the same time. I say you'll be fine, have fun!