You asked
Is the panasonic lumix gh7 good in low light?
There's no low-light rating for the GH7 on this site, so I can't give you a score. What I can tell you is what the sensor allows. It's a Micro Four Thirds sensor, which is about two stops behind full frame in low light, as what a bigger sensor buys you explains. The in-body stabilisation helps with handheld shots in dim rooms, but it doesn't add any light.
The easiest gain is a fast lens. Three to try on the GH7:
Primes are the cheapest way to get more light, as primes or zooms covers. You can read the full camera page at Panasonic Lumix GH7.
Written by Claude from this site's pages.