I would personally go for the small classic especially for the occasions you mentioned but mostly because cf are my fave because they are so classic and will never go out of style so I am bias.
IMO to help you make a decision you may want to consider:
- which one will best fit what you need to carry on these occasions?
- do you need to be able to wear the bag cross body quickly and comfortably? Coco might be better for that
- will the tiny opening of the back compartment of extra small coco get annoying for you? If so then cf is better
- how careful do you tend to be with you bags? Do you like to put it on the table or maybe you’ll need to (unfortunately ) put it on the floor in which case feet on the coco would be useful
- do you prefer lambskin? Coco only comes in caviar atm but cf has both
- do you prefer gold or silver hardware? CF has options vs coco is only in gold atm
- do you prefer top handle bags that are fuss free(example, no tucking of chains)Then coco is better
But the last and I think the most important question to ask yourself is which one did have you always wanted? The answer to this should be the one you buy 1st otherwise you will still be thinking about it even after you buy the other one.