Usually not much farther than gpu boost 3.0 will achieve on its own.
Versus a good open air cooler? No i highly doubt it, unless they are binning chips for whatever hybrid card you want to buy.
Maybe 100mhz or so past what gpu boost 3.0 will achieve on its own, on average. My 1060 will hit 1974mhz on its own, I can manually get it up to about 2080mhz stable any beyond that and it starts to artifact and eventually crashes. And thats at 55c or below with my msi gaming x card and a slightly tweaked custom fan profile.