It might be the wrong size phyiscally, but a larger battery as long as it is still EFB is completely fine electrically.
You can program the car so that it better understands the capacity when you fit a larger battery, but at best it makes a few percent difference to the calculated SoC for the Stop/Start.
The voltage is exactly the same regardless of capacity.
The AA shouldn't fit a battery that doesn't physically fit, but just in terms of capacity, that will cause no issues.