[Right Wing Assault]

these cars can be programmed to hear / cool the battery and passenger car, using the plugged in power source before the owner gets in the car, so that the car’s battery is not wasted for that purpose

On a cold winter day that will get you about 5 minutes until you need to put the heater on. Same for the A/C on a hot summer day.

[NavVet]

True, but bringing the car from 0 up to 70 or from 100 down to 70 would take a tremendous amount of energy. If you program the car to start the heater or A/C while it is still plugged in, all of that energy saved is available for use. Of course, the range will still be reduced, but not as much.