May be anybody know which km range this car when outside air temperature about -30 degree of Celsius?
Not yet, but this winter some of the northern owners (Canada, Norway) should have that info. AFAIK cold itself is not that big drain on the batteries, but winter road conditions and heater are, so expect to have quite a drop in range.
Start with 20% as an initial guess.
20% is a drop or 20% from range?
Actually I found the biggest loss in cold weather was while the car sat in a cold outdoor parking lot. I assume the battery management was minimized and hence much range was lost. If you parked in a heated garage this loss would be minimized.
Until recently cold weather charging @ 120V was also greatly hampered.
That measurement error from batteries being cold should have been fixed. IE it initially shows less range than you actually have if batteries are cold.