It looks like the only performers who are there live are Paul Rudd, Tom Hanks, Tina Fey and Kenan. (Tom flew in from LA to do the show so as long as he was stuck there, why not go on lol). Steve Martin and Martin Short sent a video message.
They are showing filmed bits they made during the week, and Christmas sketches from past seasons. Only a few band members are there.
They all seem kind of shellshocked while they try to be funny and introduce the bits. It's a weird vibe.