found this the other day, i think it seems pretty good. My washer nozzles are constantly freezing up, so i wonder if this would help.
Amazon.com: Hot Wash Wiper Fluid Heater: Sports & Outdoors
60F doesn't seem too hot to crack a windshield, and you'd just have to find a way to wire it to turn on only when you want it.

Amazon.com: Hot Wash Wiper Fluid Heater: Sports & Outdoors
60F doesn't seem too hot to crack a windshield, and you'd just have to find a way to wire it to turn on only when you want it.