I wonder what would happen if you rewired all the 24kWh Leaf electrical parts, including the balancers and such in the battery case, to all new cells, like has been done in the past with 2015-2016 24kWh Leaf cells in older 24kWh Leafs, but this time using higher ah rated cells, or even doubled cells (in back of car or on trailer, etc.) Would the Leaf go into turtle mode and shut off once it thought the battery was "dead" based on the Ah's a 24kWh battery should have or would it keep going until actual voltages drop to their "dead" range? Would the Leaf be able to recalibrate it's GID's and estimated capacity based of the oversized cells or would it freak out and show an error because the voltage wouldn't change as expected after so many Ah's or at certain electrical loads?
I would only hope that the Leaf would continue to run until cell voltages were low enough to trigger turtle mode and then shut off. In that case you could theoretically take nearly any set of lithium ion cells of the same voltage range (30kWh, 40kWh, 60kWh, Tesla's 100kWh, etc.) and wire them to the individual components of the Leaf's battery management systems and then have a Leaf of whatever kWh value you want. Of course physical size, weight and how you would place or replace things like battery temperature sensors and warmers would also have to be considered. Of course in making your own battery pack this way you could also incorporate your own thermal management system while you're at it.