This isn't a "technical response," but it is an anecdotal response. I drove the 2011 LEAF until it had lost 7 capacity bars, a range of 26 miles to Low Battery Warning, and just under 60K miles when the battery was replaced under warranty.
What seems to be the general consensus is that high state of charge isn't the best for the battery, but high heat is much worse, but exponentially worse is high heat AND high state of charge. Living in Maine and Maryland, you're probably avoiding a good portion of the high heat degradation.
I believe the batteries in my LEAF were wrecked by the dealership in Tampa leaving it charged at 100% for the entire time they had it, as it sat out in the heat of the Florida Spring, Summer, and Autumn. I am surprised that a yearly battery report gave only four stars on something instead of five, as even at 7 capacity bars down I had everything with five stars. It shows how irrelevant the annual battery reports are. I used to charge at L1 for about a year after I got it, leaving it outside the garage where it was cooler, but I don't think there is any significant difference between L1 and L2, and even QC as long as it doesn't heat the battery to a great extent. I really only ever saw six temperature bars maximum, with occasional five temperature bars in the winter here in Florida.
As I got further and further down in range, I started keeping the LEAF at a higher state of charge, and at the end I too was charging to 100% at every opportunity, just to be able to get anywhere, and this is the key part, being able to get back home. I did feel that this was contributing to the further demise of the battery, but I don't have any scientific evidence, I think the decline remained at about the same rate.
One other small detail about charging to 100% is that the charge rate tapers down, so the inherent overhead electric consumption of the LEAF while charging becomes an added inefficiency. Add to that the regeneration is negligible at 100% SOC also, so there are a couple more reasons to live with less than 100% SOC when possible.
I now have the new battery, and I am trying to keep it down around 70% SOC maximum, and 20% SOC minimum. One of the forum members, AntronX suggested the 70%, and he is pretty knowledgeable so I'm taking his advice, and it hasn't been any inconvenience. I don't know if this will help it or not. Obviously if I have a long distance to drive I'd charge it to 100%, as others who have long commutes do. I didn't have "range anxiety" even as low as my battery got, I knew what parameters I had to live within. I did a 50 mile round trip even at 5 capacity bars down, but obviously with not much to spare. I found out too, if you're getting closer to the maximum range, slowing down really helps to extend the distance it will go. Tony Williams has provided an accurate chart for people to see on the forum, and with LeafSpy you will also have a true knowledge about the battery situation, so I would definitely advise people to get it. The program also provides a good bit of extra information, such as tire pressures too, so it can be very helpful.