I'm still on the Nougat Beta on my regular S7, but recently by battery has been atrocious, especially standby battery life. If my phone is at 100% when I go to sleep, it's around 50% when I wake in the morning. It used to be around 3% overnight drain. It's also just as bad during the day, draining around 15-20% per hour when not in use.
I have disabled all features I do not use, cleared Play services cache, cleared the general cache. Any other suggestions would be much appreciated!
Yes, I have tried that on a couple of occasions and it doesn't really help much unfortunately.
Normally , Android OS, Android System and Device Idle are accounting for most of my battery usage, with screen on time being around 1 hour 30 mins.
What locating method are you using on the phone? Settings > Privacy and Safety > Location > Locating Method.
Try 'GPS Only'; and also only enable Wi-Fi and Mobile Data when you need to use it - and then monitor it for a bit. This'll help narrow down whether it's fluctuations in the signal that's tugging on the things you mentioned above and causing that power drain.