I was just in NY for a November theater trip and I was looking for weeks, maybe even months trying to see if Assassins tickets would pop up but it just kept showing as sold out. While I was in New York, I looked at tickets and there were two pairs of tickets available for the following night which I purchased immediately. There isn't a bad seat in that theater, it is very intimate. I also noticed at least 6 empty seats when I attended so not really sure what's going on, if there are last minute cancelations etc. You can also try the digital lottery.