I think all this worry and complaint about battery cooling and deterioration is all a myth that some are using to either discredit the Nissan company or for Nissan to blame battery deterioration on temperature rather than time. If all members recall their past experience, they may see my point.
Except for those hot climates where daily temperatures are over 100 degrees, the reported posts on battery temperature are irrelevant. If posters are complaining that their battery temperatures have "spiked" up to 100 or even 112 degrees, their complaints are totally trivial. First, if you are driving in a 70-95 degree ambient temperature (and the car's battery is working hard to propel you at high speed), what is so terrible if the battery temperature goes up to 100-110 degrees? That temperature is just slightly above your normal body temperature. If you touch something with that temperature, then you would hardly perceive that it is hot at all... Maybe a bit warm. I cannot imagine that that temperature would DEGRADE any rechargeable battery. Man, my Samsung cell phone gets so hot that it burns in my pocket at times, and it still continues to work fine for years. In my opinion, battery temps of 120-140 degrees would be more damaging than at 100 degrees.
Second, this is my theory of what is happening. I have used rechargeable batteries since the 1970s in all types of products, and the following NEVER changes. Rechargeable batteries do an amazing job of holding and giving out electricity, with many cycles of discharge and charging. Truth is that rechargeable batteries have still not progressed that much. The lifetime of a cordless drill battery (my closest comparable battery to EV batteries) only last 2-4 years before they do not hold a charge.
So, it is my "conspiracy theory" belief that (except the crazy people that buy Leafs and live in desert and tropical climates) all battery deterioration that people report is a NORMAL expression of the battery's normal lifetime. Think of it, my battery has over 1500 charging cycles and is still (for now) strong. THAT is amazing. Of course, Nissan would never "to your face" tell you that their batteries are strong for only 2-3 years and go downhill from there. No one would ever consciously buy their cars then. SO.... It is easier to blame high battery temperatures (caused by users), which give us users the "fantasy" that we can extend the life of our cars with careful use. Its like the TV commercial fantasy that if you eat probiotics and organic food, you will live to 120...
I, personally, voluntarily took the plunge with my Leaf and hope that by the time my battery needs to be excised, batteries will either last longer or will have greater capacity. I really think that Leaf owners should consider themselves as trailblazers who are testing out the future technology of our planet. They should not be considering themselves as "discriminating consumers" that EXPECT all their products should work perfectly, like their continued fantasy that their world should be also perfect.