Wondering why there is no resort availability anywhere for Nov. 5-7. Not typically a busy time. Are there that many people going just for the 50th? Or is there something else going on?
The hotel reservation algorithms sometimes exclude dates that are only the highest demand days without any lesser demand days. Try adding 1 or 2 days to the front and/or back of your dates and see what pops up, if anything. Good luck, hope you find something!