It seems clear that na-ion batteries will replace large scale grid storage especially in cold climates. This isn't another hyped up battery.
IMO, for large scale, nothing beats pumped water storage if you have the right conditions for the required lake. No risk of a bad cell causing a fire, no chemical degradation, no cooling or heating required and zero to full power within seconds just like a battery.
One of the few pumped hydro facilities in the US had a catastrophic flood