As of now what we can do is, switch off the 'back ground data' for the applications as much as possible that you feel not required to run in back ground. I disabled the 'ok google', which is always listening what i am speaking, will run the audio hardware in background. Also, I am not using face detection, that will eat more power. Even WhatsApp also I restricted for back ground data. This helps me a lot on battery saving. Yes, you are right, 3060mAh is very less for this big, high resolution display. Nokia, hope you are listening us, at-least in future products, please take care of this low storage battery issue. The world is moving towards high powered long storage batteries. Please don't disappoint us.
to stop apps in background,
settings -> apps & notification -> <any app> -> data usage -> background data <disable>
I removed the google search bar from the screen and rebooted once. (I did a big circus to remove the 'ok google' dont remember the steps exactly, so better search in internet and do.)