Today I drove 170 miles nonstop from Steamboat Springs to Boulder Col. Temperature at Steamboat was -24F. It stayed well below zero for the first half of the trip (-28 in Kremmling!). Model S performed flawlessly. Arrived in Boulder with 90 rated miles left. Energy usage was 304W/mile. Went over two mountain passes (Rabbit Ears @9450ft
and Eisenhower tunnel @11000
ft). Speed for the trip ranged from 45 to 75 mph on mostly dry roads.
For the round trip Boulder/Steamboat/Boulder the total energy usage was 110kWH or 324W/mile. Pretty damn good