I don't think they run out of the ornaments as it is one per
DVC membership so at 4:00 PM there is no problem getting the ornament. You receive the ornament when you leave. Pictures can be a bit tricky. The lines for getting photos with characters get pretty long, so we never wait for them as we get photos taken with Mickey and Minnie in holiday costumes at the parks. But Donald and Daisy are there and often so are Chip and Dale and sometimes Goofy. So to be first or close to first in line you would have to get there at least 2 hours before the party. Not that I would ever do that. They do sometimes run out of cookies or rice crispy treats. But then in the past one person would take a dozen cookies when they only had 4 guests. I think one year you had to turn in a ticket stub to get the items and you were given tickets for each member of your party. I cannot remember if that was continued last year or not. But it kept people from being greedy.