i'm so excited, i can actually help you with this! i never know the answer to muppet questions, but i happened to see your message in wanting to post a question of my own.
i have the video you're looking for, called "Sleepytime Songs and Stories" it has Dance Myself to Sleep, If Moon Was Cookie, Snuffle Lullabye, Everybody Sleeps, and Imagination and furthermore, i can be of additional info. b/c i loved these songs so much that several years ago i bought the video and the CD, the CD is called "Dreamytime Songs", and has: Sleepytime on Sesame Street, In Your Imagination, If I Were
(one of the greatest kermit songs ever IMHO, esp. for non-joe raposo) If Moon Was Cookie, Snufflelullaby (worth it just to hear snuffy and big bird talk, i love hearing snuffy say "oh bird")
, Afraid of the Dark, Imagination, Naptime, What Do I Do When I'm Alone?, The Frogs in the Glen (another treasure why i impulse bought it when i came across it), Read Me a Story, Dance Myself to Sleep, Little Things, and of course, I Don't Want to Live on the Moon, which up until that time before major mp3 downloading i only had on an old recording from a friend. hope that helps