If you used 385 grams of dough to make a 15" pizza, that is around 3 ounces more than a 302 gram dough ball for a 14" pizza. That shouldn't rule out a 15" size. Maybe I am missing something that isn't showing up in the numbers, so please let me know if my numbers are wrong.
Peter, yes same numbers I got from calculator with 2% residue. No the reason I said "Ah ha!" was your saying
"it was a combination of low dough ball size (302 grams), which leads to faster cooling, and the small amount of yeast that explained the dough's longevity."
I then agreed with your statement that the smaller ball size aids in the doughs longevity as they cool fast. Now kick that up to 385g, or even 350g, (still a notable difference from 302s) and I was attributing this to the possible premature death of the last doughs. I was agreeing with you that these balls were too big to cool fast as I noticed they blew up in the containers too fast, my last that went 6-7 days were de-gassed in day 4 actually, so that's what I meant. This also answers your question GB about them rising, they rose too well in the containers, just not when they were cooked, lol.
BUT I must say 350gs is a much thinner dough when stretched to 15" than what the 12" 235g balls produced. Despite any thickness factors told by a calculator. (No offense to the calculator)
Maybe you'd also call 350 or 385gs balls "smaller" as well though? If you do I can say my experience is they act much differently in the fridge than a 302, indeed. Either way I'm with Mike in his 375g for a 14", as I used a 385 for a 15", though his dough as you can see is not as thin he's closer. Stretching 350 to 15" without a rolling pin is quite an accomplishment, at least for a 7 day old dough. I did the 350 once, Mike nailed it's making it to 15" on the head with his humorous response here. http://www.pizzamaking.com/forum/index.php/topic,7761.msg84033.html#msg84033
It was a great pie though, see how thin and all, but not 15". It was when I then kicked it up to 385g to get safely to or over 15" that all hell broke lose. So my 350's were better in longevity than the 385s seemingly.