Willym my garage is heated, I leave a 1500 watt radiant heater on all winter. If the temp is around say 4 below C the radiant heater keeps my garage at a nice working temp. When it gets colder I will add another 1500 watt heater. I've been doing this for years now because in the winter time I like to build projects, that includes a double kayak, a teardrop trailer and 4 jeeps. Hydro is not as expensive here as in other locations, I've estimated it costs me about $365 for each year over and above normal power costs. The benefit is the garage is always warm and no condensation on my tools. When it gets between 20 and 40 below there is a backup woodstove though honestly at 40 below zero going outside is not all that attractive. We dont head south in winter so $365 is a bargain