Hullo James.
A nice sentiment and instrument selection but to my ears there are some odd sounding chord changes here and there that you may want to change.

Also, These lyrics (You kissed me, last Christmas, and left, oh so fast) suggest she left last Christmas after a kiss but in the last verse (This house's getting colder with each Christmas Day) you are suggesting more than 1 Christmas has passed.
You could change that line to "This house is much colder on this Christmas Day".

Could be a nice song with some changes.

Vic