Maximum Cold Ferment Time

I have 2 dough balls in my fridge which have been cold fermenting for 5 days, or 120 hours. (Since it’s just me and my wife, we can’t use too much at a time.) This particular dough is the MODERNIST PIZZA NEAPOLITAN-style. (See recipe below.) 

The next time I can use this dough is either tomorrow, after 144 hours of cold ferment, or the day after, which would be 168 hours of cold fermentation.  

As of right now, it looks and smells okay. But at what point should I discard dough as “over fermented?” I’m thinking of “blind baking” or “par-baking” it as an experiment. What results can I expect?   
(My wife pointed out that ready to use supermarket pizza dough sits who-knows-how-long in the refrigerator case at the store.) But what’s the limit?