This was fun! It took me a bit to figure out the flexibility in the theme (I first got MYS63D*Me, _____ and I[---] and then expected the elves to all be at the end), but once I got that I really liked how well the fill worked!
Loved discovering the theme - it was really cleverly implemented and I liked that the theme told a story through the revealer! If there was one thing constructive I could say it is that a few clues (e.g. 13A13APlayed music... Might be used to call your grandma?[----------]) had the fill in the clue (grandma > GRAM) but in those cases you can usually just replace with a synonym.