We recently had the good fortune to have cold snap here in North Idaho. We hauled out the Thundervolt and did a little stress testing on our updated frame.
The morning we chose was 10 degrees F. We kept a mostly-charged battery in the freezer overnight and chilled it to 3 deg. F.
We found that pushing, we could generate over 550 lb. of force with the Thundervolt. That is as much as our 2 largest guys could generate. The tire began to spin before we could stall the motor. Pulling was just over 350 lb. before the tire spun (pulling is always less effective).
These numbers represent the maximum forces we generated with a 8000 load in both free-wheeling and braked conditions.