I cannot imagine a temperature cold enough in the US for the oil to expand so much that it would crack the filter cap. And if the coolant was properly mixed and in decent shape it shouldn't have frozen enough to crack the thermostat housing and reservoir. Hopefully when you fixed the damaged items you also flushed the respective systems of fluids and installed fresh.
The diesel machinery probably used these heaters more to prevent the fuel from gelling in the engines rather than to keep the oil and coolant warm. Since gasoline does not have a gelling issue, that could explain why such a system is less common on gasoline engines. The engine block heaters tend to be installed more for the driver's comfort than to keep the coolant or oil from freezing.
Now with that said, I've never experienced a North Dakota winter and we hire a lot of graduates from there. They often make comments about looking forward to our mild Iowa winters.
-Rod