Average 980m overclock?

I know a lot of people have mentioned overclocked 980ms still staying in the 70cs. What's the max overclock from anyone here on the forum?

and my main question is - given the general clevo cooling systems and cool room temps, what type of overclock is there when keep temps in the high 80cs and low 90cs before thermal throttling?

I know it may decrease lifespan, but for someone who upgrades every year or two, how far can you push the 980m and keep it below 93c?

thanks