filming in winter + ProTune mode + 1080p60, however, is a frustrating experience. 30min is typical. if battery is brand new then maybe you can squeeze 45min out of it.
My experience as well. That's why I have two batteries and a battery pack. Although I'm not doing much filming right now, it's more hassle than I expected.
This usually lasts all day of regular use.
I now have 3 batteries and never have to worry about battery life.