Should I still push through with our group vacay with ex?

Half a year ago we all went to a Ukraine ski trip with my then girlfriend’s group of friends. It was really fun and we all enjoyed each other’s company. Which is why we all decided to do it again next year. We’ve booked our tickets I think a month before my ex and I broke up. Such a bummer I know. But since we remained friends, she and I put the thought of our vacation to the side. Now that the year is about to end, our companions are already over-excited for the upcoming trip. I’m not sure though if I should still push through with it. The dates would fall on our anniversary week. In fact, the day would fall on the middle of our week-long trip. Would it be awkward if both of us will go? Should I still go with her friends even if she’s not there?