Norway!
Wild camping is fine anywhere as long as you’re more than 150m from the nearest house and it’s not cultivated land.
Take your own food and some booze*, swim every day in the fjords, stop into campsites with pay showers when you need one and just pay for the showers.
Can be done pretty cheaply, and you could get to the far north and back i that time without it being too much of a mission.
* booze – there are import limits, you can obviously be cheeky, we weren’t checked. If they do find more on you than you’re allowed, they confiscate the extra it or you pay the duty on it rather than throw you in prison, so not the end of the world.