Even with a tether, I'd fear free floating fire above a tent city.
When I was a little kid, my brother used to make these out of dry cleaning bags. Took him a while to figure out fuel source and weight ratio. Finally got one going and it flew beautifully, until it wandered in front of a rather large dish on top of a mountain. PHSTTT! Suddenly security was combing Navy housing. He told me we hadn't been out all afternoon, we'd been watching cartoons. It wasn't until decades later when I was in the Navy myself studying electronics that I realized, oh shit, exactly what happens when you hang a sheet of plastic in front of a powerful and sensitive transceiver. Yikes.
The lanterns don't work all that well at high altitude, and if it is windy, forget it.
I'm too jaded to think up a good sig-line. Need more coffee.