There are also some specials released on iTunes in HD and some HDTV airings in torrent sites, I’m not sure about the quality of them, though.
The HDTV 1080p version of “Race for Your Life, Charlie Brown” is 4:3 open matte, unlike the Amazon Prime version which is cropped to 16:9. The HDTV however does have a logo in the bottom-right corner at certain points.