You can avoid most of the automated antics kbeck describes by not using the Automatic setting in winter, and selecting appropriate fan speeds yourself. (Control of heater output temperature is still automatic, according to the temperature you've set.) I like to wait until the sun comes out before going anywhere on winter mornings.
^ Even I would say not really. But: We got the block heater installed at time of purchase, and they dinged us $400 (CAN). Now, Honda Canada shows it on their website, for something like $235 installed? The install is NOT that easy, mainly due to poor access. If you can get it installed by a dealership for somewhere around that second number, I'd be inclined to go that route. We're on the west coast, milder winters than even the east coast I think. Some people will call this nuts, but anyway: we use the block heater year 'round. I try for a couple of hours before first start up of the day, minimum one hour in a pinch. And we stick to that, pretty consistently. My main concerns are improving fuel economy (faster warm up) and protecting the engine: the hardest wear on an engine is during the start up, and the block heater typically brings the coolant temperature up 20~30C above the ambient air temperature, really gives it a head start.
How hard is this? I'm pretty happy with my "Spartan" Prius Two, but in retrospect wish I had a back-up camera, (now standard across the line) and 3 door SKS functionality would be nice. You get spoiled walking up to the drivers door and just being able to open it....and then it seems "frustrating" when you have to go to all the trouble of pushing the button on the fob to open the hatch. However, I suspect I'm really just getting lazy.
It's hard, with quite a bit of wiring and disassembly: How to add SKS to the hatch and passenger door on a 1 door SKS Gen III Prius | PriusChat We get by with the reprogrammed driver's door SKS to unlock all doors/hatch. We do like the Camry's 3 door SKS though, especially being able to walk up to the trunk and open it without pressing or touching anything else.
