I totally agree with the comments directed towards skipping the event, but if I may quote from the bible here...
"Put your faith into action and use your mouth to speak His word, PROFESS. We have to be doers of the Word, not only hearers. James 1:22"
In this context I have found that if I profess my sobriety to those that seek to derail my goals, I was surprised by the positive reaction from those I spoke to. Many I think were proud/envious/supportive of my choice to not drink "just because there was a party" Now, I didn't come to the party with a big sign on my forehead, but as I was asked why I was not drinking, a simple "I'm not drinking" response was generally all it took.
I'm new to the whole sobriety thing, so take my 2 cents for what it's worth.