Living in Montreal,Canada I've had block heaters on all my cars and was very glad I did.
The suggestion for an inline-heater is very good. These typically only need to be spliced into a coolant hose & circulate the coolant by thermal action - so entire engine is warmed, not just the upper (typically) block. They generally use same or less current than block-heaters, too.
Warmed-up engines are easier to start, get windows defrosted faster & heat interior faster. 3-4 hrs is all thats needed for block heaters.
Lucky that my 2016 TC LWB wagon came with factory block heater. Now if I could just lift it an inch or so (inexpensivly) would be great.
PS: Having a "trickle-charger" available for really cold weather is good - especially if, as me, you mainly do short trips.