Sorry to hear about your medical appointment, Vin... Fingers crossed it goes well for you and you are back to yourself very soon.
As for the dates, I am equally happy with postponing or whatever works best for everyone. 26th May, however, I don't think I could do, as I am going to be abroad, I think. I could do the following Sat, that is 2 June. It might even get warmer and sunnier, perhaps allowing some of us to go for a drink or a lunch afterwards...
It would be a pity not to have Vin presiding over the proceedings.