It is normal, really...and the above is a key difference in addition to the huge temperature difference.
If he had driven the EXACT same drive as you at 255Wh/mi, he would have used:
223/209 * 150rmi. = 160 rated miles (not your 150 rated miles). To travel 120. So that is part one.
But he did 299Wh/mi - but he was using the heat!!! At 40 degrees outside that is a steady state 3kW or so. At 70mph that is 3kW/70mph = 43Wh/mi
255Wh/mi + 43Wh/mi = 298Wh/mi
QED?
If he had done the same distance drive you did at 299Wh/mi, he would have used 172 rated miles.
Also by my calculations you should have used closer to 140 rated miles, not 150. Obviously pretty common to be a bit higher in reality with time spent in park and prewarming the cabin.
255Wh/mi/223Wh/rmi*120mi = 137 rated miles.