I might be pointing out something that may be obvious (my apologies if so): the "storage" 70 degree high end of the range mentioned is in Centigrade and this is 158 degrees Fahrenheit ... the "people" scale used in the US.
So, if the inside of your car at the windshield gets to 150 degrees (Texas and US measure in Fahrenheit), the -20 to 70 C range
should suffice, I think. But, I don't have any personal experience yet with dash cams though, so ... check it out for yourself.
Also, the
operating temperature high of 60 degrees Centigrade is 140 degrees Fahrenheit ... so, while driving, might be good to turn the AC on ... certainly for the people in the vehicle anyway!