I would not be surprised if we see a 345-mile rated Model 3 sometime before the end of 2021, but:
1) It won’t be due to the battery.
2) It will have the same actual range as the existing Model 3 under ideal conditions and the same energy available.
3) It’ll need to have a heat pump.
4) It’ll be using a different 2-cycle to 5-cycle scaling factor due to the heat pump giving better cold weather cycle results, so will magically get a better rating, like Model Y. It’ll just be more difficult to make that rating under ideal conditions. But it will most certainly do better than the current vehicle in chilly weather.
Maybe they’ll announce the 345-mile vehicle is in production (I thought I read something about Model 3s in Europe with heat pumps but have not been paying attention) on Battery Day and everyone will lose their sh** even though it has nothing to do with the battery?
Maybe in 2022 we’ll see denser batteries? No idea. Seems like they will need them for Cybertruck, for sure. Something has to give.