You have already outlined an exit strategy. Make sure you use your own transportation so you can get out on your terms. I someone asks if you want a drink, "Say, No thanks. I've had enough," and that won't be a lie, because you realized that when you had your last drink.
For me, having an exit strategy, and having set my mind to barrel out without apology the moment things got tempting was a confidence builder. In addition, at that first event, I never even had an urge to drink. I looked at everyone else, and was just grateful that I wasn't one of them.
Days wise, you are about right where I was when I had to face this for the first time. You can do it, and when you come through just fine without feeling you were walking the edge. Your confidence and opinion of yourself will take a major leap up the ladder, and your sobriety will be more solid than ever.