I'll focus on the last.
Use self-generated energy, water, etc
Self-generated energy usually means solar power, as wind power doesn't really work well at small scales and hydropower requires a river which most places don't have.
The problems with solar power are two-fold:
- Sun shines only at day, so you need huge batteries to use solar power at night.
- Away from the equator, sun shines well during only the summer. In winter, there's no practical way to get reasonable amounts of solar power. This means you'd need to store the excess power generated during summer for use during winter. Batteries aren't cheap enough to store that amount of power; pumped hydro and underground hydrogen storage can store it but they are relatively expensive too for seasonal storage and they don't really work at small scale.
So in order to be able to use self-generated electricity, you need a place near the equator where the summer and winter have nearly equal amounts of sunshine.
In Europe that would mean Greece, southern Italy or southern Spain. Most of Europe is quite far away from equator. United States would have locations that are closer to the equator, and thus a better place for self-generated electricity.
Apart from the land near the equator, you need big honking batteries and the ability to replace them every 20 years or so (or if you use lead-acid as opposed to lithium-ion, the replacement cycle will be shorter).
The only reasonable option apart from the "near the equator" plan is to try to see if you can find a place where you can install a micro hydro plant. In optimal cases, if the river is flowing all the time, it might eliminate the need for batteries. Finding the land allowing the installation of micro hydro plant would be tricky, though.
A different approach (with very low energy efficiency and lots of labor required): you could of course buy a big forest, clear some of it away and build your house there and run a generator with wood gasifier to generate your electricity. However, that would require some modification as standard generators run on fossil fuels only, and also the generator needs to be rated for continuous use as an emergency generator will break if used continuously for decades. Also keeping that generator running requires lots of labor unless you construct an automated wood feeding machine which eliminates some of that work. This approach however has a ridiculously low energy efficiency and is very wasteful. It's far better to create electricity from other sources such as wind.
However, I find your question a bit amusing. What is it about self-generated electricity that make it so desirable? I'll make a different suggestion: why don't you partner with thousands of other investors, collect all your money into one joint stock company, and construct a wind farm? Owning 0.01% of 100 MW wind farm is far better than owning 100% of 10 kW solar array, because wind production capacity factor is 30% and solar usually maxes out at 15% in good places.
My approach is the stock investing approach: I make myself self-sufficient by buying stocks of companies that make products that I need. This includes electricity generation companies.