There were several '60s TV series that had feature versions, most of them sitcoms.
McHale's Navy had two feature films released during its run.
Munster, Go Home! was shot right after
The Munsters ended, and
The Man Called Flintstone came out just 4 months after
The Flintstones ended, as a kind of series finale.
Dark Shadows had one film released near the end of its run and a second shortly after it ended, but they were out of continuity with the series, I gather.
I can't think of any examples of an hourlong drama series having a contemporaneous or immediately subsequent theatrical version. Maybe it would've been harder to fit into the budget and schedule?
Batman did film an actual feature film between seasons 1 and 2 at the height of its popularity.
The original plan was to do the movie
first, so they could budget for more elaborate vehicles and sets and produce a library of stock footage they could then reuse in the series. But ABC insisted on an earlier start to the series, so they had to shoot season 1 before the movie, which is why the Bat-copter and Bat-boat don't debut until then. But I think maybe they were able to use some of the movie's allocated budget to build the sets for the series. Though I'm not at all sure of that part.
The Man From Uncle 'films' were just a couple of two part episodes (aired in the U.S.on TV), that were released as films in European and some other countries theaters, and the latter was not all that uncommon in the 60s for expensive high profile U.S. series.
The 2-parters had additional footage shot to add more sex and violence for overseas markets. There's one where they brought back David Sheiner in a bald cap (since his hair had grown back since the episode) to film a new opening sequence of his character breaking into a military installation and killing a bunch of guards -- only to cut to the opening scenes of the TV episode, in which he’s still waiting
outside the gates of the installation and breaks in
again. There's also a tacked-on subplot with Yvonne Craig, who's clumsily inserted as the one answering the radio when Solo calls into HQ, flirting with him for a few moments before forwarding him to the person he actually called.
The hourlong pilot episode of TMFU had a whole new subplot filmed to expand it to movie length for overseas release, with Solo on a side mission investigating the murder of an agent killed early in the pilot. The subplot was later cut into a season 1 episode, combined with a parallel plotline taking the place of the original plot, and with the agent's name redubbed from Lancer to Dancer (no relation to April Dancer, introduced later as "The Girl from UNCLE").
