I was speaking informally earlier, but if we make things more precise then I think we're pretty much on the same page.
I think you're right when you say:
>In colder ambient temperature the propensity to generate current decreases. However, the quantity does not.
Presumably, the car stops running when the battery's propensity to generate current ("voltage") falls below a certain threshold. If that propensity to generate current does decrease when it's cold, then a cold battery will hit that car-stopping threshold earlier, right? Assuming the battery stays cold.
That's all I meant when I said "a cold battery has a shorter range".
And when the battery warms up, its chemical reactions speed up, increasing the voltage and pushing the car-stop threshold into the future. That's what I meant by "As the battery warms up, the estimated range should go up as well."
The battery's "state of charge" in the plot from Musk's blog post does go down overnight. Whether that's due to self-discharge, some system in the car that used a bit of energy overnight, or some temperature-related measurement effect (or a combination of those things), I don't know. I just thought it was striking that the "estimated range" dropped so much more than the "state of charge" (at the 400 mile mark in Musk's plots).
Does that put us on the same page?