This episode is very strange to say the least because you would expect there to be some special plot but there isn't one. Even with the longer than usual length, there is still no plot.
What happens then? Well basically Beavis and Butthead are just chatting about Christmas and watching a load of music videos and that is really it.
There is a special called Beavis and Butthead do Christmas (which is not included in the whole series of Beavis and Butthead for some reason, it's more of a stand alone type thing if you know what I mean). It has a lot more of a Christmas plot to it than this. So it is probably best that you go for that one instead of this.
As for this episode, if you liked watching Beavis and Butthead's review on music videos before, you should like this as it is mainly all like that, no joke. If, like me you always wanted to skip the videos, it might be a better idea to skip this whole episode.
A few slightly humorous comments, but nothing really special.