I brought my 2003 from upstate NY to Central Ohio on a car dolly in the big snow storm in March. We ran the 4 ways on the Prius because the tow dolly lights kgetting covered up. I started the car, set the heater temp on 60 and took off. When the temp in the car reached 60 the ICE would shut off and when the temp got down to about 55 it would start again on it's own and run until it got to 60 and also charge battery. 12 hours of this and we got home only to find snow so deep we couldn't get in the driveway even with the 4X4 tow vehicle, but no adverse effects on the Prius.
