The TV film special A Very Brady Christmas first aired in 1988, 14 years after the original series concluded. The majority of the original cast returned for the flick, except for the original Cindy Brady, Susan Olsen, who was on her honeymoon at the time and temporarily replaced by actress Jennifer Runyon. At the time of its airing, A Very Brady Christmas was an enormous television success, to the point where CBS even ordered a spinoff revival series called The Bradys that only lasted six episodes.

Sorry, Brady Bunch fans! Hopefully, someday soon, the film will appear with its siblings on Paramount Plus for easier accessibility.

Source: https://www.distractify.com/p/where-to-watch-a-very-brady-christmas