In my experience, even without SMC Fan Control, OSX will ramp up the fans on its own after a certain point, like around 90˚C. Which is ridiculous, but whatever. In Boot Camp, as far as I can tell, they won't ramp up at all regardless. Fan management under Boot Camp is practically non-existent apparently. And because of the way the Boot Camp drivers work in Windows, you can't even access the SMC without turning off the Boot Camp keyboard manager altogether. I've looked for solutions, and there is one rudementary program somewhere that you can use to access SMC Fan Control in Windows, but it is very glitchy and not really supported because it's a home-brew quick fix.
In DIY PC circles, idling at 35~45˚C is the ideal range, 55˚C is considered a good target under load for most chips, with "hot" ones going into the 60's. Above 70˚C is generally too hot for comfort (for the longevity of the hardware) and anything that gets up into the 80's is just outright poorly designed/cooled. This means that MacBooks live beyond the edge on a daily basis. My CPU and GPU regularly idle around 50~55˚, even on a cooling pad with fans blowing on it. They max out in the 70's under full load, but only because I set the fans to max (6k rpm). I don't dare let them linger above 80˚ for too long.
So I hatched a plan.
Wanna know what I'm gonna do next week with my MBP17?
I'm gonna take it apart, take off the heatsink, clean off the thermal gunk, and use a reasonable amount of PROPER thermal grease, instead of the globs of cheap goop that come from the factory. I'm giving
Arctic Silver's "Matrix Thixotropic" thermal compound a try. Might look into that thing that people do to dampen the track-pad click noise a bit as well.
Bravely going where few dare to tread.

Wish me luck.