A party or Wendover?

A group of people here at work are going to Wendover on a bus, and have invited me to go along. Now, I like most of these people, but I wouldn't say they are my friends or anything. I just work with them. So, I ask my friend Michelle if she's going... no, she has a birthday party. Bummer.

Then Michelle emails me and invites me to the party! It's her best friend's party, and she and I have met a few times and she is really a fabulous person. But I wouldn't know anyone else there.

So... do I go to Wendover with people I know but aren't my friends or to a party with a couple friends and the rest complete strangers?

Hmmmmm.....