Very nice!
I have two oil-filled radiator heaters in my GH but it gets a lot colder, for a lot longer, here. My favorite is a programmable one I picked up at HD - it can be set for two different heat settings for two different times (e.g., higher in the day, lower at night).
I have to run both at night since it's been consistently getting below 20degrees (F) at night here.
I originally had an oscillating heater as a backup to the radiator but it would blow the circuit when it kicked on and there is nothing worse than not knowing the power is out in the GH!
(Stupid old house with bad wiring)
Have you put a high and low thermometer out there to see just how much heat you will need?? You may only need a backup one for a few nights a season.