Temperature could well be an issue... I am in Bismarck, ND, right now it is 36 degrees with sleet, my signal levels are impeccable 95% of the time better than -70dBm with constant 4G (I live and work within 1 mile of a 4G tower, typically in line of sight of it). Don't laugh though, we see plenty of 90-100 degrees days plus ones that are -20 for highs too (touchscreens don't like really cold temps, or gloves!)
Right now I am at 36% battery, 15 hrs 48 min on battery and 9 hrs remaining... 1 hr 24 min phone calls, 1 hr 37 min screen time, 41 min WiFi :icon_ devil:
Now, if I have to run into the rural areas for work and get into some area that that 3G is not even available, or you have to drive out of town and get on top of a hill to make a phone call... yeah, my phone sucks power out of a battery like fruit in a juicer! Sometimes I am charging or changing batteries (I carry a spare pair of standard batteries and a stand-alone charger in my laptop bag) multiple times a day, so I get where you are coming from.