Can you invite (bribe) a coworker to tag along w/ you? Not as awkward as bringing a date and it would still be a buffer for you.
Or can you make friends w/ the person who is catering/managing the affair so you can "help" him/her and keep yourself occupied and appearing to be involved.
I'm not exactly introverted but I am very rigid in terms of the things that I do and don't like. And yes, being forced to mingle w/ a group I find boring/pompous/very different would be torture for me and I would come across as rather badly. I totally get the concept of not wanting to fake it.
I think as lomg as you say hello to everyone and spend at least 30 mins there, you have done your job.
But also remember, these ppl could be your next (better-paying) employer if they like you.