I go every year from 12/24 to 1/2. I always liked that the decorations stayed up for so long. For me, Christmas didn't end until I left Disney. If they turned it over intra-trip, it would have felt like my trip is over.
But 1/12 is waayyy too long to have them up. The Christmas crowd is long gone by now. There's always that house in your neighborhood that you pass with their lights up wayy too long - Disney is becoming that house!