They start going up with the first Christmas party in early November, are fully up by Black Friday, and are taken down usually by the end of the first full week in January.
I was there this November8th-13th. While all the decorations were not up everywhere, a majority were in the parks and you can tell the Christmas season was upon us.
Yes, we were there Nov. 18th-26th and everything seemed to be fully decorated except for maybe the Worlds at Epcot. MK will definitely be the first to be ready for MVMCP
