Well, sure, multiple DC FCs on a Leaf in a day can drive into the red on its temp gauge. Or, I guess high ambient temps can push it fairly high. 117 F is pretty crazy. Ever wondered how Hot your battery can reach and still be funtional? - My Nissan Leaf Forum
got his battery up to 137 F (~58.3 C).
I'm in a hotter part of the SF Bay Area but I've never seen its temp gauge that close to red and I monitored actual sensor temps via Leaf Spy (the app that guy used) instead of the crap temp bars. Also, my last Leaf, a '13 didn't even have a CHAdeMO inlet so it's not like I could roast it from DC FCing. L2 charging barely heated up the battery.
I also took steps to keep the battery cooler while it was at work (see below):
However, if I were really hardcore, I would've charged it overnight outside only instead of charging it all at work. But L2 charging is free at my work and I don't like paying Pacific Gouge & Extort to charge at home.
Yes, it seems like the 40 kWh packs (available on non-Plus model year '18+) are holding up pretty well from a degradation POV. The 62 kWh packs on Plus Leafs seem to be holding up ok too, but they're kinda new. Leaf Plus didn't go on sale in the US until ~Spring 2019.