Yep, even with a manual transmission in neutral you can feel the lubricant viscosity bringing up the clutch at -30C. My car's outside temperature display doesn't show temperature below -30 and it takes time for the radio to start working. Seat warmers are really appreciated as you don't need to wait for the engine to warm up enough to heat the interior.

Block heaters run about 400W. It helps a lot to have a garage. When it's this cold, I also run a battery charger as living in a walkable neighborhood, I can go several days without using my car and the battery sags in the cold.