I have not hit a problem yet, in spite running a high battery temp during a 90+ degree day across Iowa. That said, there is a video from Germany, where he saw reduced charging at high temps.
Here in Chicago, we usually only get 5-10 90+F days a year (and its usually cooler at night), so its rarely a concern. If I lived in Phoenix, I might think about where I park my car before making a call. (if you are usually in a garage, your probably ok), but if in 120F sun every day, I might pick a Tesla with the overheat cooling, even though it costs a fair amount of range.
2019 SV Plus Silver 6/19 purchase 7,000 Miles
2013 Leaf SV
100 Mile Club Member (Number 87)
Max distance on 13 Leaf: 120 miles
Max distance on 19 Leaf: 242 Highway 4.5 miles/kWh