It won't be dead but there is a mass exodus on 1/1.
Crowds pick up for marathon weekend (the next weekend after New Years) but we've always had great experiences and haven't found the marathon crowds to impact our park experience overall too much, but we always make good use of EMH.
Crowds do not compare to Easter when we used to go, or to the New Year's Eve portion of our trip so we find early January a wonderful time

This year we'll get there 1/4 and are looking forward to it.
I've heard crowds this year are just larger in general so it will
be interesting to see if the different than other years.