The second "Hänsel und Gretel" show got canceled because we had lost power. And my ultimate question of the longest time came to my mind again; how did concert halls and opera theaters manage to have lighting back in Mozart's time (18th century)?
Finally I got around to do my research. In opera scenes of the movie "Amadeus" there are very bright footlights and enormous chandeliers on stage. And those are exactly what they used.
On this website "Stage Lighting Museum" you can find out about the history of stage lighting. In the 18th century, this is what they had:
There's a bit of sunlight from the windows but it was surprisingly bright with the chandeliers. I guess with the right kind of candles (not tea-lights for sure!) you could make do?
Pit orchestras also used many candles back then; in the pictures, orchestras seem to be located closer to the stage foot lights than these days. Today, orchestra pits are located almost under the stage and it's really dark. Without stand lights we can't read notes on our music.