I've managed to plan my annual holiday trip to NYC on Santa Con day a few times. This year I noticed it on the train and near Grand Central, but not many other places. They managed to move it down to the East Village and end it around Times Square it looks like. So I was able to avoid it by mostly sticking to midtown and a little up the East Side. Everyone I saw was fairly behaved too.
A cute moment though was when some Santa Con-ers were standing on a corner outside the train station. A few were figuring out where they were going while one guy was just leaning against a mailbox letting his friends figure it out. A little girl walked by with her parents and stared very wide eyed-ly at the kid. He bowed his head and said "Merry Christmas" to her. A touch of responsibility and maturity on a party filled mission was nice to see. LOL