metastars said:

What about the 1080p version previewed on Youtube here?

https://www.youtube.com/watch?v=97nnHjUrLvU

Is it released anywhere?

Despite that nice-looking clip, there's no such thing as a 1080p version of the Holiday Special. It was shot on video, and will only ever be as good as video-quality resolution...which is not that good. You can upscale it all you want, and maybe lose a bit less of the original resolution when you rip it to digital, but it's never actually going to be 1080p. It's really just polishing a turd.

Had it been shot on film, you'd easily be able to go 1080p and even higher on it, because the resolution would be available. But apart from (most likely) the cartoon segment and the outtake clips from Star Wars, none of it was shot on film stock.

--SKot