When I see a movie about people trying to live alternative lifestyles, I think of the travel agency Jim Carrey visits in The Truman Show, with its alarming poster of an airliner getting struck by lightning, accompanied by the slogan: “IT COULD HAPPEN TO YOU!” A similar deterrent seems to be in operation whenever people reject conventional ways of living in the movies. More often than not, the parents go crazy, the kids are screwed up and you come out of the cinema thinking: “Well, I’m glad I didn’t try that!”

For all its merits, Debra Granik’s latest film Leave No Trace can’t help but agree. It’s the story of a father and teenage daughter who live off-grid in the middle of a national park. Despite their minimal carbon footprint, it is not exactly a sustainable lifestyle: they are evicted by the authorities; dad (Ben Foster) is a traumatised war veteran who can’t cope with “civilisation”; daughter (Thomasin McKenzie) discovers what she’s been missing – like friends.

There is often a fanatical dad at the root of these misadventures, such as Viggo Mortensen’s Captain Fantastic, who also assiduously forest-schools his six children on why capitalism is wrong. Of course, the wheels come off when they reconnect with the real world. Even worse is The Glass Castle’s Woody Harrelson, who sees the “free-spirited” lifestyle lose its lustre for daughter Brie Larson when she flees to the embrace of education, gainful employment and running water. Harrison Ford goes one step further in The Mosquito Coast, dragging his family into the Central American jungle, telling them the US has been nuked. Again, he is obsessively against American consumerism, and his family have to go along with it.

The thing with most of these films is that their basic diagnosis is correct. Our conventional lifestyle models are flawed and we all know it. But every time a movie tries out an alternative, it gets shot down like the airliner in The Truman Show. These stories flirt with radicalism but the moral is usually conservative. Leave No Trace takes a more nuanced approach, and gets closer to the real reasons people might want to turn their backs on society.

But if you want to see a family who really make the alternative lifestyle work, you could go back to 1960 and Disney’s Swiss Family Robinson. Shipwrecked on a desert island, this wholesome tribe turn it into a tropical utopia, complete with traditional European family values. There might be pirates and wild animals but it’s clearly better than Switzerland, and when rescue arrives, most of them choose to stay put. See? Sometimes it does work out. It could happen to you.

Leave No Trace is out on 29 June