Hottest 43°C. Coldest somewhere around -20°C.

I’m also in Canada and have noticed that the power savings from an ROI perspective is minimal. That said I think it’s still beneficial. Just simple things like lights turning off when you leave. Furnace/heat/ac changing to an “away” mode. Heat/ac getting disabled if window/door open for extended periods of time. Most of my devices and automations are either about convenience (lights dimming when playing a movie, lights automatically coming on at 1% for nightlight, sprinkler schedules) or collecting data. Collecting data did lead to an energy savings as I saw how much the garage baseboard heater was actually running in the winter and so I kept the temp lower.