Is it 2 years sobriety or 129 days? 629 days? I have been sober for well over 2 years and a half and the cravings are really different now. From the start I have not avoided alcohol or social situations because my drinking was mostly done in secret and being in non-social situations was much worse.
The bottom line is this: if you feel you are not ready, be curious about yourself. Investigate why? Why is this craving coming from an invitation? Alcohol is everywhere and you have made the commitment not to drink for a long time. Why would this be different?
I believe you train the muscle of sobriety with every ocassion you expose yourself to your own cravings, but also that nothing is worth a relapse. If you know thisis dangerous, avoid it. I drink alcohol free beer from time to time, but never as 'replacement', normally after a very long run. But I used to do this when I was younger too. I would not plan a replacement for the drink either that would imply 'prentending' that I am drinking. Is this the reason you are in a danger zone? Are you ashamed of your sobriety in this kind of event? Do you worry about what the others think?
Obviously I am not raising these questions for you to answer them here (unless it helps you) but in case they help you work out whether you must go to this, and if so, what is the danger, where is it coming from and how to address it.
Good luck