Of course that's more efficient but won't matter (from an environmental perspective, might still make economic sense) in a few years when all electricity comes from carbon free sources. If this won't be the case then heating will be the least of our problems.

I think you're optimistic if you think we'll have zero carbon electricity production in a few years, at a scale that will allow us to replace all NG and oil heating with electrical, especially without heat pumps.

Even if we make it a primary priority, and try to maximally ramp up both wind, solar and nuclear production (+ storage as needed), I don't think we will be able to do it in less than 30 year, 20 at best.