Our experience is that it's no problem , we have often stayed overnight at many woodland sites where there are fire places with grills set up by the locals ... these are much safer than making your own fire place ..

have you looked at the "Schlafen im Stroh" ? sleeping in hay .. there are many farmers who will let you sleep in their barns for a small fee , they provide a linen sleeping bag and usualy a breakfast if you want it.

I used to run young adult survival courses ( woodcraft/bushcraft) in UK , so if anyone fancies the idea of some alpine (lowland valleys ) I would love to join in...