Does refrigerating Diet Pepsi (Splenda + AceK) meaningfully extend shelf life?

Suppose I fill a refrigerator with aspartame-free (Splenda+AceK) Diet Pepsi that has a nominal expiration date of July 7, 2018. If it's continually kept refrigerated at 40 degrees Fahrenheit or less, how much additional shelf life am I likely to get compared to storing it at room temperature (~74 degrees, give or take)?

I know that with ASPARTAME-sweetened soft drinks, refrigeration makes a HUGE difference to shelf life... and conversely, storing it at "Florida garage" temperatures will dramatically accelerate its decomposition.

• Does Splenda + AceK enjoy the same huge increase in shelf life from refrigeration (vs 75F room temperature) as aspartame? Realistically, if cans of Splenda+AceK-formula Diet Pepsi with nominal expiration date of July 7, 2018 were purchased in late April and kept refrigerated to 40F thereafter, how much additional shelf life could I reasonably expect to see (vs the nominal July 7 expiration date)? September? October? God forbid, Thanksgiving or Christmas?

• Can soft drinks sweetened with partially-decomposed Splenda+AceK be resurrected by adding fresh Splenda (AFAIK, AceK isn't available in the US for purchase as a separate product... though I'd love to be wrong...), or is it like aspartame, where the decomposition product ruins the taste regardless of how much fresh sweetener you add?

Why it matters: Pepsi recently switched Diet Pepsi back to their old, disgusting, "diet-tasting" aspartame-based formula. For me, the old aspartame-based formula is NOT a viable alternative. Prior to 2015, I drank Pepsi One almost exclusively (and paid a small fortune for it, since it was only available in cans, from a few stores... and when it finally went on sale, those stores usually didn't even have enough 12-packs in stock to meet their minimum purchase requirements to GET the sale price, let alone stockpile enough to last until the next time it went on sale). When Pepsi made Pepsi One's formula the new "aspartame-free Diet Pepsi", I was delighted -- finally, I could get the one I liked in 2 liter bottles, buy it in abundance when it went on sale, and get it from "normal" stores & vending machines. Now, they've taken it away from me again, so I'm trying to stockpile as much as I can get my hands on to buffer me until a viable alternative becomes available.