Perhaps this should be under the stream for suggestions for the website but:
Why not send an acknowledgement when people register for one of these events? I tend to notice them, maybe register, then think a day or two before, Did I register? And then register again. Sometimes, and again and…
There seems to be no way to check.
I hope someone is telling the Sauternais. The last time I visited Sauternes and Barsac it was closed!