I'm getting one step below that level of performance at 1.081v on an EVGA 1080 SC w/EK block. That seems like a helluva lot of volts to force into this thing for a measly 12 MHz more performance. And is that 70 C under air or water cooling? It would have to be under water, and if so, that's really, really hot for a watercooled 1080.
I can see this being kind of fun to play with for people, especially for people who intend to do LN2 or sub-ambient via phase change or TECs or whatever, but it certainly isn't very practical for normal use.