Block heater question

My 625 Gator is stored in an unheated shed in northern Wisconsin where current air temps are running in the -20 degree range. The machine is generally not used between late Dec and early March. I use a trickle charger for the battery but I have wondered whether I should install a block heater. Do other users in severe condition areas use block heaters...would the use of a heater unit help maintain the engine condition under static rather than cold temperature starting conditions?

Thanks for the advice.