I go to weird places with my gear. I carry one extra (original) battery for each camera (1-series and 5-series). I have never run out, being in Africa, Norwegian mountains or anywhere else. As an extra security I have a transportable solar panel, which, depending on the amount of sun, is an extra security.
My experience with third party batteries and chargers are 100% negative.
1DXII, 5DIV, 5DSR, 8-15/4L, 11-24/4L, 16-35/2.8L III, 24-70/28L II, 70-200/2.8L IS II, 100-400/4.5-5.6L IS II, 200-400/4L IS 1.4x, 17/3.5L TS-E, 24/4L TS-E, 35/1.4L II, 100/2.8L IS Macro, 300/2.8L IS II, 600/4L IS II, Zeiss: 15/2.8, 35/1.4, 55/1.4 Otus, 85/1.4 Otus, Profoto B1