That's a secondary effect. Primary effect I had in mind when commenting was the movement of the emissions from the local tailpipe to the electric plant (which is very far from 100% emission-free today).
OK, I'll play along. Suppose I drive my electric car an additional 450 miles. That will consume an extra ~100kWh of energy from the battery, which will require me to buy an extra 115kWh of energy from my electric utility, which will require them to generate (or procure) an additional 125kWh or so.
Are there any emissions associated with that additional 125kWh of consumed electricity? If so, where? If not, why not?