I don't see any impact from the Glance Screen to the battery. When I am not looking at the phone, it is face down to keep the screen off, or it is closed up in a case.
Having the additional info on the Glance and Lock screens is one of the reasons I choose Windows Phone, though Android is starting to close that gap.
Battery life is 95% user related.
I unplug my phone around 10am, plug it back in around 1am.
I have other devices to supplement my non mobile, online time.
The 950XL sadly does not get the love my Tablet does, and nobody is really trying to get in touch with me. As a result, I often do not have my phone when someone does call.
But I have a small battery pack and multiple mobile power options available, should they be needed.
I have experimented a lot with my start screen including empty tiles and beautifully arranging tiles inspite of having to place them where its not most convenient to me but I always revert back to this design after at most a day lol. Notice how Facebook, messenger and onenote are easily within the reach of my right thumb so that I don't have to use both hands when I am half alert and focusing on something else while also browsing through Facebook or taking quick audio notes on onenote. I was so proud of myself when I set my start screen like this the first time. Also this was the day that I realized that windows phone is the best phone ever in the whole wide world windows phone forever 
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