Yes, this is possible, but I guess only if you have your own vehicle.
I have done two road trips together with 3 friends through France experiencing all the things listed, except for the vultures.
On both road trips we didn't have a clear goal in mind, and chose a destination from day to day.
The first road trip was around the Vosges mountains, on the second road trip we went south from the Netherlands without a clear city in mind. We ended up in Montpellier.
Both road trips lasted for about 10 days, but I could easily do it for three weeks.
At the end of every day we escaped the main high ways and started driving on the smaller roads in France to find a proper wild camping place. We used the map to look for green areas with a river or a lake next to it. At that time I didn't know but wild camping is mostly legal in France
Almost always did we find a proper place (if not an official camping was our plan B), but it did cost us quite some time.
Some suitable places are fenced off, other places don't have a road nearby.
Sometimes we could park the car next to the road, walk through a thin layer of bushes and trees and find a huge field or a small lake very suitable to camp by and relax.
Because we didn't plan and didn't pay much attention to the map I can not name the places we stayed close to, but I guess, as I tried it from north to south, this is possible through all of France.
Yes it's possible if you have your own car, stay of the main roads and look for green areas on the map.