This
reddit thread shows a Leafspy screen cap of a 24kwh LEAF with almost 175k miles and over 9500 cycles! That also seems to be about the max life out of these batteries as the results are that it's about shot, which answers my question of how long I can expect to limp this car along. Also, this gives some clue as to how many more cycles these batteries would be good for in a stationary solar storage capacity, which is my plan for them once I'm done with the car.
An update on my own car over a year after creating this thread is that I'm now over 101k miles with basically no change since last year other than my kids are getting bigger and my requirements for range are getting longer, so I'm finally going to install a 240V L2 charger in my garage, but even then I might have to upgrade to a larger battery than this 18kwh effective one before it actually degrades any further.