Fran, those wattage statements seem very high. I just looked up my heat pump and it only draws 1920-watts. My electric range is nowhere near 12,200-watts and that's if everything was running at the same time. That calculates to more than 50 amperes. My frig is connected to a 20 ampere breaker, but only draws about 8 amps. Now, all of this stuff I have is fairly new and low energy consumption rated, so maybe that has some bearing on the figures.
Either way, my electric bill only averages about 120 a month, and that's with an oxygen generator running 24/7.
Chas, if I lived in your part of the world, I would probably go for the largest system I could find to do the job as well. There's no such thing as having too much electricity available, especially given the weather patterns you have to endure every year.
Good luck,
Gary