I have also been wondering such things, also if melting starting more on the Chukchy or Barentsz would have an impact on the minimal extent, but I couldn't find anything clear.
I feel that extent is not a very good parameter when we are at the maximum or at the minimum because small changes in the % of ice in the sea can have a huge impact on final values. It's more the weather than the climate that is considered when values oscillate.