Holidays are opportunities for programs. You don't have to interrupt your curriculum to have music and movement for those programs. Here's an example of what you can do to create your own arrangements with input from your students.
For K-1, write a simple phrase like "Snowflakes falling from the sky, Singing children pass us by". (titi titi titi ta Rest, titi titi ta rest.) Teach them the poem then have them create a body percussion part that matches the rhythm. Ask: Can you name some winter (or Christmas) things? cold wind, gray skies, peppermints, hot cocoa etc. Create one or two ostinati from these using body percussion. Move the body percussion to unpitched instruments. Create melodies, even simple so-mi melodies for the poem. Use one ostinati for a drone on a bass or alto xylophone. Create a form, ABA, Rondo etc. Add a movement section and you've got an interesting piece based on your regular curriculum. For older students, extend the poems, have them play the melodies on barred instruments and create their own movement.