If you read the book when it was published, Galt’s Gulch was plausible. Reading it now, the scenario where you take a small group of producers and completely hide yourself where no one in the rest of society can find you is too far fetched.
If they really do make this a movie, it will have to be categorized as sci fi and not a thriller.
In the first chapter of Part 3, I pointed out that the modern surveillance state makes Galt’s Gulch impossible unless you locate it off American soil.
Maybe it's not so implausible if we look at it from a different angle: Rather than people running off to a hideaway located somewhere else, maybe they could stay put and create a sort of underground economy.
That seems to be what today's criminals do. There's an underground economy all around us now with stores operating as fronts and so on.