Second winter here, ~20 000kms, I haven't seen any signs of degradation so far. Charge it to 100% every day on 240v and drive it in sports mode almost allthe time. I'm not worried about the battery. Time will tell, but with the 8years/160 000 kms warranty, why shoud I? Lots of my friends also have evs of different makes and it seems so far that battery degradation is a Leaf problem only because it doesn't have a BMS. My brother changed its 2012 leaf for a 2019 bolt because of that.