I'm not sure when the Jolly Old Elf comes out, but Epcot is great for Santa. You can even pick which Santa you want (England, Canada, America). Have you checked any schedules online? If you are there right after Thanksgiving, he'll be around. Have never been there immediately before Thanksgiving (although we once arrived on Thanksgiving itself!)
Just checked online and it appears Christmas Storytellers don't arrive at Epcot until the 26th. However, Santa is at the Santa Chalet starting the 19th of November. Christmas Parade in Animal Kingdom should be on while you are there, but cannot remember how Mickey & Minnie are outfitted. Do remember Chip & Dale had scarves and hats.