We actually do have a song for Advent, focusing on the first Sunday's traditional theme of hope. (For this year, it might go best with December 3rd's second reading.) Consider An Advent Thought.
For either Christmas pageants or for Christmas Eve, we offer
The Shepherds Recollect, for 1 or 3 men's voices with guitar. It recounts the visit of the shepherds to the stable of Bethlehem.
Another piece for Christmas Eve, with guitar and optional piano, is
He Arrives. Since it has an original melody, it would probably work best as a solo or unison ensemble.
And, we do need to mention our story, The Lamb's Tale, mostly just for your own Christmas enrichment, or possibly for a study group.
Finally, for the Sunday following Christmas, consider our piano-based solo Keeping Christmas. If your choirs take a break after the holiday intensities, this could work nicely. Plus, with the Sunday after Christmas being New Year's Eve in 2023, the rededication aspects of the song are especially appropriate.