I don't know if battery heaters are a common feature on current EVs. I'd think it would be particularly useful for LFP cells, which can be damaged if you try to charge them when they're below freezing. They can be discharged safely (if not efficiently) at much lower temperatures, which means you could "bootstrap" the car in cold weather by using the battery to heat itself until it gets warm enough to charge (without which you can't use regenerative braking).
It wouldn't be that far-fetched to imagine a battery cell with a built-in heating element (e.g. an internal 1 ohm resistor across the battery terminals) that, when activated, keeps the cell at at least room temperature and shuts off when the battery gets up to temperature. Normally you'd only activate the heater when charging or driving.
Although maybe that's not right... if a large amount of energy is "lost" when the battery is too cold, that energy has to go somewhere. If it ends up as heat anyways, maybe it's really functionally equivalent to having a heating element in the cell. In which case the solution is probably just to insulate the batteries better.
Temperature change needed for complete loss of Greenland ice sheet: between 1 and 4 °C. (That's a change by, not a change to).
Effect of complete loss of Greenland ice sheet: 7.2 meter sea level rise.
Your attempt at nit picking, if it were valid, would actually makes it much worse: a temperature increase sufficient to turn "-22c" into "we don't need to worry about cold batteries" requires close to double the difference between today and the highest estimated average global temperature ever in the biological history of the planet, and that temperature happened before trees had evolved.
For example, naïvely adding 22 C (22.5 says Wiki) to the average so that the coldest was no longer below freezing, your Fort McMurray would have a new July average high of 46.2 C, which is above the current average of Death Valley 10 months of the year and pretty close the other two.