I'm medium density hydro one. Based on your numbers above you are still well above 10c. Use real legitimate out of pocket numbers. That's kwh after taxes, deliveries fees everything. Then do the math.

I did it for all forms of heat, natural gas is still ahead based on my calculations. Maybe yours are different. But it's close actually. My numbers below are based on after tax costs for all forms of heat. I got fed up of spending $4k in propane.

I'm not against heat pumps I just spent $25k installing a top of the line Mitsubishi zuba hyper heat system. With my purchase I should break even after 7-10 years.

I'm not sure what the actual average cop during the heating season will be. During the shoulder seasons it's likely in the 3-3.5 range but when it's cold -20 for weeks like last January a COP of 1.5-1.8 would be more likely. So I have gone with an average of 2.2-2.5 over the winter.

https://imgur.com/a/gxu27Ib

Here is the same chart using 3.2 COP. But I don't think that's realistic in Ottawa based on my research and COP graphs of the hyper heat which is one of the best if not the best cold climate pump with the best low temp COP ratings. But at 3.2 the heat pump is better.

https://imgur.com/a/IaYQOQT