It's not quite as bad as that, as electricity is a more efficient fuel source for many applications, including heating if you have a heat pump and the cold side

It's not quite as bad as that, as electricity is a more efficient fuel source for many applications, including heating if you have a heat pump and the cold side isn't a lot colder than your target temperature. For transport it's much more efficient - 1kWh of electricity will get you a few times further than fossil fuels containing 1kWh or energy. But your point is still valid, we certainly need to more than double grid capacity if we want to rely on electrification to avoid lifestyle changes.