I seem to remember that the "Menagerie" movie I saw all those years ago in a movie theater was from a 16mm print so it is possible that the movie was simply the regular episodes not edited together although I saw a preview from a TV station in New York City in the early 90's that showed "The Menagerie" as a feature film on one of it's late night movie programs...
The local affiliate in Oregon also ran The Menagerie as a 2-hour movie. But they just showed the two episodes back to back. There may or may not have been a special intro. as well. I don't remember.