Hello Zach!
I believe Bariloche is a sure bet for you to take. We have one of the best profiles for snow productions in the world thanks to the level of accesibility to locations and service infraestructure.
We serve important commercial productions every winter, and August is indeed to sweet spot for the kind of setting you are looking for. We can offer a variety of coastal and fjord-like locations with forests and snow only minutes away from the hotel and even downtown Bariloche, plus other smaller localities in the area.
You can step off the airplane and start scouting right away thanks to our international airport, only two hours from Buenos Aires.
Hope this is useful! Please check:
http://www.barilochefilm.com/patagonia/nieve/