I'm sorry, I'm afraid I garbled my explanation rather badly. Let me try again.
1. Forget Paris. I was using that as a hypothetical example and have no wish to get married there.
2. My fiance and I intend to settle in the UK permanently. I want to move there at the end of October, as my lease is up on my New York loft, my cat will be ready to go by then, and we have already been apart for 2 months now, since my fiance left the US.
3. My only question is about the wedding itself -- whether I could leave for JUST THE WEDDING (as though we were going on vacation) then return to the UK and live normally. I know it sounds like we should have married before leaving the states, but time and jobs did not permit such planning after our engagement. However it's rather a moot point since the wedding I was thinking of having in the States (on a boat) would have to take in the summer or fall, and the fiance visa only gives me six months to get married. It will not be summer or fall in the six months after I arrive.
I think what we will do is have a private getaway for the two of us to actually do the deed this winter, and then have a separate ceremony for our families and friends, at our leisure, later on.