Okay just in case someone decides to search the same problem I was having lol I found that deleting or (better) renaming the cuda_supported_cards.txt file allows Premiere Pro to use the Cuda Hack which allows GPU accelerated rendering, supposedly. So far the render bar remains yellow so this gives me high hopes that it will reduce export times, although the GTX (x)80 cards are the CUDA supported for Premiere so I hope it doesn't wear my 660TI down.
EDIT: Holy s**t, it actually worked, I think. Down to 20min average render time with a watermark. But it's really pushing my PC.