I would assume that they would still do the cruise - but it wouldn't be Wishes that you would be seeing, as I have heard that they do a special fireworks show on those nights of
MNSSHP.
Unless I am mistaken, if you are planning on a pontoon boat, the maximum people allowed is 12 - and I think that is the most for any of the specialty cruises. There is one that accomodates 7 and another that accomodates 10 people.
We are planning on renting one for a night on our trip - as long as we can get a reservation!!