AZ:

Your math is right on the money.
Only need to consider the conversion losses.

No power converter is 100% efficient. There are also charging losses within the battery. Assuming an overall 80% efficiency (conservative) the charging time or the receptacle's wattage would have to increase an additional 25%

But your basic conclusion is correct. For very fast charge, a dedicated "electron-filling" station, would have to become available.

Of course, we smart and educated members of this forum, would do an overnight charge, when peak consumption is lower.