How do we answer an uncle who wants to bring his own alcohol to our dry wedding?

Uncle Ray replied to the menu message with, "No problem, I'll bring champagne for our table." The message had said we weren't serving alcohol.

The venue allows it, but we've chosen a dry reception. We both want an evening we can remember without managing a bar, and we've ordered drinks we like. We aren't presenting the decision as a judgement on anybody else's wedding.

Ray says he understands us not paying for alcohol. I think he has heard a budget decision when we've made a hosting decision. Mum says one bottle at one table hardly counts. My partner says agreeing would mean explaining why the next table can't do the same.

I want Ray there. I also want him to arrive knowing what we've invited him to, rather than having this conversation beside a cooler in the car park.