The Pigeon - Holiday edition

123456789101112131415161718192021
Across
  1. 3. The co-founder of this luxury footwear brand was a UAL alumnus (5,4)
  2. 7. Dasher or Dancer (5)
  3. 8. Firm determination often found on Jan 1? (10)
  4. 9. The halls are usually decked with boughs of this (5)
  5. 10. Shakeable world where storms last seconds (9)
  6. 12. Required action under 2-down (4)
  7. 13. Political group, or a December 31st necessity? (5)
  8. 15. The James Bond actor who studied at UAL’s Drama Centre before joining MI6 (6,7)
  9. 18. No two are alike (literally or politically?) (9)
  10. 20. Holiday drink suffix (3)
  11. 21. Where ornaments hang (4)
Down
  1. 1. The riverside complex home to the National Theatre, BFI, and Hayward Gallery (5,4)
  2. 2. Half of a kissing hazard? (6)
  3. 3. "___ to the World" (Christmas carol) (3)
  4. 4. Iconic three-word warning heard on the Underground platform (4,3,3)
  5. 5. Type of log cake or tide (4)
  6. 6. Square to watch before the ball drops? (5)
  7. 11. The electronic card used to pay for travel on the Tube and buses (6)
  8. 14. Christmas is also called this (4)
  9. 16. ___ calendar is pretty common around this time of year (6)
  10. 17. "One-horse open" transport (6)
  11. 19. Central Saint Martins' King's Cross home was originally built to store this food staple (5)