If you live across the pond in the US and have a free weekend, it's pretty easy to do this sort of thing here, too.
Many national forests and lands administered by the BLM allow 'dispersed camping' in the wilderness. You're encouraged to use existing sites along forest roads, but the rules are usually pretty loose. Search engines don't do a great job of indexing the USFS or BLM websites, so you might have to poke around a bit to find a 'camping information' page for the area that you're interested in. But you can find some basic information here:
https://www.blm.gov/programs/recreation/camping
Sadly, it's not all roses and sunshine. The author got told that he technically needed a permit to be in the part of the wilderness that he stumbled into, and you'll probably get some of that if you spend much time in BLM lands. People throw up false 'private property' signs and gates all the time, and those sorts of people tend to have the 'Cliven Bundy' sort of attitude that they have more of a right to public lands than others. There's no arguing about land usage with someone who points a gun towards you.
We also see the sort of aristocratic land grabs that he mentioned here; there are a lot of BLM lands which are now surrounded by private property, and those property owners are not required to provide access to the public lands which they surround. It essentially cedes "multi-use" public lands to the people/companies who own the properties around them.
It's too bad we don't have a right-to-roam in the US. It seems like the sort of thing that would fit in with the ostensible national ethos of freedom and independence.