I was there this November 5-9 and MK was fully decorated, DHS was fully decorated (both started their special holiday offerings on the 8), Epcot was not decorated, and we didn’t visit AK so I couldn’t say. Disney Springs was decorated by the 9, the Contemporary gingerbread display was up, WL was not (we looked, lol) and GF gingerbread was starting to be assembled, I believe. Didn’t check any other resorts other than POFQ (because we were staying there) and while decorations weren’t up they did have a cute snowflake hunt around the resort.