If it's similar to my experience, on December 30 at the MK, they opened a
backstage walkway to get from the castle to the flag pole area (came out on the street next to Tony's).
The girl with the blue wand in the pic gave the "no photos" spiel right after I snapped this one.
There also seemed to be a coned path leading off to the Tomorrow land area too. There was probably one on the Frontierland side of Mainstreet too.