Thanks for the report. I remember liking Season's Greetings when I saw the British television production that PBS showed long ago.
The play was seen in New York at the Joyce in the summer of 1985. That was the summer when three productions from regional theatres were brought in to play at the Joyce. I think the hope was that this would become an annual thing, but I think that may have been the only time it was done. Season's Greetings came from the Alley in Houston.