I’ll try – not sure they’re Christmasy enough for your list:
– Sufjan Stevens: The Greatest Gift
– Gaelynn Lea: Grace and a Tender Hand
– Edward Sharpe: Dear Believer (if a song with the lyrics “Now comfort’s rooting pigs for my blood” can be an xmas song?)
– Edward Sharpe: Home (though more of love song, it’s still about home in a joyful way)