The date given in the paper - November 5, 1955 - is the same date traveled to in Back to the Future
This episode completely ignores the events at the end of the last episode; that storyline continues as if without interruption in the episode following this one.
The appearance of the wall is a nod to the Stephen King book the inspired the TV Show "Under The Dome."
The movie listed on the marquee at the Cinematheque is "The Bark Tower: A Dog's Lighthouse". The Dark Tower is a series of books written by Stephen King.
Episode is remarkably like Star Trek: The Next Generation 'Remember Me' where Dr Crusher is the only one to notice that everyone around her is disappearing because she is trapped inside a bubble. The main difference here is that this is Christmas themed.