I got the game on the release. The first time I launched it, it defaulted to Ultra settings yielding me a lovely 4fps. I dropped it down some and the menu was running smooth, but then I started the game. In the first outdoor location, the framerate simply died. Even on minimal settings it would not pass 20, and in the Fort Joy square it dropped to consistent 10.

Now, since I'm using a laptop I decided to check the default video adapter. Sure enough, it set itself to the integrated Intel card. I manually launched it with the dedicated 850m, but it did not change anything. That already was a huge red flag, since I'm 95% sure that initially it launched with the Intel one. I then went ahead and changed the setting in Nvidia control panel, and even in nvidiainspector, which allows you to manually set control bytes for every application. This would virtually force everything to use the more powerful card.

Nothing changed. I then changed the global settings to use the 850m for everything by default. Nothing changed. Now, I would perhaps accept the explanation that my machine is shit (albeit I doubt it, since literally no other game performed this poorly) if it wasn't for the last effort test. I disabled the integrated graphics card altogether and tried to launch the game after restarting my PC. It crashed on launch, every single time.

Is anyone else having those issues? Is there any known solution to this?

Running on GF920M
Nvidia CP indicates that dedicated card working on it.
Do not forget that you can always manually set default processor in Nvidia control panel

Not what you want to hear, I know...but buying laptops with the idea of doing anything more serious than playing Solitaire in terms of gaming is like trying to use a buzz saw for neurosurgery...;) Be kind to yourself...a decent desktop is cheaper and far more powerful at the same time--and it's upgradable, where laptops generally aren't. Use your desktop for "real" gaming and use your laptop for mobile work and you will be *much* happier. I say this because you can't imagine how many gadzillion posts I've read just like yours--somebody buys a "gaming laptop" because it seems like the perfect compromise, only to find out that it is anything but that--and often people pay through the nose for "gaming laptops," too. Just a suggestion to file away for next time...;)