Based on my experience with my Model S and Volvo PHEV; the answer is "it depends". If the vehicle is left outside, not plugged in and cold (<40 degrees), when you start driving the car will drain a bunch of battery power to warm both the battery pack and the cabin; this will drop your range by 25%. If however you keep the car in a heated garage, or if you leave it plugged in and schedule pre-conditioning then the battery will be warm when you unplug and so the range impact is probably more like 10% depending on how much cabin heat you want.
Most defiantly YES! I am on my 2nd electric car (the 4xe coming will be my 3rd). I remember with my BMW i3 and it's 80 mile range, in the summer I could get to work and back (about 60 miles) no problem, but in the winter the range extender would almost always kick in before I got home. Yes, cold weather sucks the range out of your battery big time. It's just the way it is, nothing the car makers did wrong. So yes, if we get, what is it, 24 miles electric on a nice 70 degree day, I will be expecting around 16 or so on a 32 degree day...
Note, this is just the battery itself. Obviously if you have a cold car and crank the heat, it will take even more. That's why I always pre-condition while plugged in before leaving.
Battery's like to be kept and operate most efficiently at the same temperatures as we humans do say approximately 75 deg F. The 4xe battery is cooled by refrigerant from the engine and heated with engine coolant depending on conditions to maintain the ideal temperature range. Its location tucked under the passenger seat also allows it to benefit from inside cabin temperature management. This does mean you have to run the engine in temperature extremes to benefit: that's why the 4xe is a PHEV as opposed to a pure EV.
In arctic conditions, range drops by approximately half.
Running the heater kills EV range as well, to the point where people will bundle up to get more range. I lol at that. Right now, EVs put buyers in the penalty box which is why hybrids still have their place.
Been lurking for awhile now. Former Chevy Volt owner. Cold definitely affects range. I would see 40% reduction on the coldest days (0F). That was with running the gas engine first, then switching over to the battery. I would expect higher losses in a Wrangler due to the conventional drivetrain layout (hypoid gears in a solid axle have higher losses that a fwd setup).
My experience is if you use the heater you'll lose about 25% of your range. Many times I'll use the seat heaters and turn off the heat until my windows fog up. Then I realize I just saved 10 cents. In short cold weather WILL lower the range. To what degree depends a lot on each driver.
We have a 2014 Chevy Volt. During the summers I could squeeze 50 miles all electric, during the winters it is down to 30-35 all electric. Engine comes on intermittently when temps are below 37 F to keep everything warm, so it is just going off of the calculations. If temps are above 37 F all electric operation is possible but turning on heat definitely drops mileage.