Paluk you were asking about block heater usage in Canada. Where I am in Manitoba it can go down to -40C in December through March and if your not plugged in you are not starting your vehicle.
Alot of people find out when it gets cold that their block heaters don't work. They then have the long hour wait for a tow truck to come jump the battery so they can start their vehicle.
About 5 years ago some vandal came through our lot when I was working evenings and unplugged all the cars. I had to wait 3 hours for the motor league to get a truck to me so I could go home.
The big thing now is energy management on the plugs. Manitoba Hydro says that the block heaters are only needed for up to 4 hours to warm the engine up, so to reduce consumption costs companies are putting devices on the staff plarking plugs to turn the power off and on depending on the weather.
Here are two examples the first is a central control unit and the second one is a retrofit that goes at each stall.
http://www.hydro.mb.ca/saving_with_ps/central_parking_controller.pdf http://iplc.com/installation.html
