Awaiting to be shot down in flames here but I believe with a G + Y hydraulic failure only the slats will will run as they will be driven by the blue system. I was taught by a captain many moons ago that it gets to a point with some of these scenarios that "you have to land somewhere" and with the greatly increased fuel comsumption I would be inclinded to stay where I was unless there is another uncontaminted runway of suitable length very close by.
Best regards
OP