Hasta La Motion!

I’m working as a compositor on a short film shot on a nikon D7000 and i’ve run into some problems with the keying.

Some of the green screen scenes were filmed pretty late in the night and without enough lights. To compensate for this i think the DP cranked up the ISO pretty high (which creates the grainy/noisy plates), and i’m pretty sure that they forgot to turn off the in camera sharpening.

I’ve tried to degrain the footage, but it only helps a little bit. Do you guys have any ideas how to solve this or should i just roto the damn thing?

Thanks in advance!