Well in my opinion, the noise on 3200 iso is still usable. And it's the fact that the 800 iso on gh5 looks so MUCH better than 800 iso on gh4, same thing for 1600 and 3200, makes the gh5 a lot better thab the gh4. By a good difference.
Sure, it's not a low light monster (because it's not designed to be) but it's an all around effective filmmaking camera. If you have 2 small LED lights and bas8c knowledge on cinematography and how to use the camera, then you should get highly presentable low light shots for sure.