The old C64 Christmas demo was a store demo that displayed Christmas scenes while playing 8-bit Christmas music in an endless loop. You didn't actually interact with it. I do see how the word "demo" could be confusing. All the searches I did came up with Christmas themed game demos like Christmas Lemmings. The only thing I could find was "Magic Christmas Toyshop" that as a demo screen saver. Didn't try it because the demo seems very limited (one song).

I ended up downloading "Frodo", a C64 emulator and played the Commodore Christmas demo. That got annoying after the 5th time but I was just wondering if there was something for the classic Mac. I guess not. The is a Apple II Jingle disk but I think it's the same one as the Commodore one.

Thanks for trying though.