I’ve read the series several times. (And pretty much everything else King has written.) It’s basically Stephen King’s Lord of the Rings. (Mike Flanagan is supposed to be working on a streaming adaptation, and I can’t wait.)
Roland isn’t intergalactic, per se, but he does, on occasion, slip between worlds.
Even though the actual story is probably a little dense for translation to the field, the aesthetic— basically the old west, with scattered technological remnants of a civilization long gone (the “old ones”) that the current inhabitants don’t really understand— would be cool as hell. With the occasional monster thrown in for good measure.
Oh, and it would give them reason to work Hey Jude into a show.