Been there, done that, with an old vampire VorGuy knew in high school. VorGuy's brother didn't get the memo and gave him our contact information three years later.....after VorGuy lit into his brother, we haven't heard from the vampire since.
Explain, nicely, to Kara, that you and Connie just don't have much in common any more and that you really don't want to spend much time with her, as it isn't going to rekindle the former close friendship.
Then, if you feel that you have to go to the event, talk to anyone and everyone else but Connie. You can run to the lady's room, get another drink, look for a waiter to get rid of the empties at the table, ask for an appetizer, or see someone that you need to have a word with. Never be RUDE to Connie, but don't spend more than a few seconds around her, either.