Please somebody write to the stupid Condo Managers in Canada! A Volt doesn't eat much power as the block heaters used.
Possibly, but not the whole story when dealing with block heaters...
http://www.mychevroletvolt.com/how-much-does-it-cost-to-charge-a-chevy-volt
Chevy Volt
Example 2 – Electricity: You drive 1,000 miles per month, your car (The Chevy Volt) gets 2.7 miles per kilowatt hour used (EPA estimated average), and you pay $0.12 per kilowatt-hour (national average) That means:
1000 miles / 2.7 miles per kilowatt-hour = 370 Kilowatt-Hours
And
370 Kilowatt-Hours * $0.12 Per Kilowatt Hour = $44.44 in Electricity per month.
http://blog.gvea.com/wordpress/?p=727
Block Heater
If you did plug it in all of the time, your electric bill would skyrocket. For example, if you plugged in the average car (1,000 watt load) for 10 hours each night, the monthly electric cost would be about $60. Just two hours would run $12 per month.
A car really only needs about two hours of plugged in time to warm up. Also, typically, it takes about two hours for a car to cool down after it has been running. So, if you plan to drive your car again within two hours, there is no need to plug in. When the temperature reaches 20 below or colder, you may want to increase the amount of time your car is plugged in, but generally not more than four hours.
GVEA recommends purchasing a vehicle plug-in timer. Instead of waking up two hours early to plug in your car, let the timer do it for you.
Worse case scenario: 4 hours a night for the month
30 days * 4 hours/day = 120 hours
120 Kilowatt-Hours * $0.12 Per Kilowatt Hour = $14.40 in Electricity per month.