Well that's embarassing. My problem was an incredibly easy fix.
Whenever I first have problems with a game I update drivers, which is why I, you know, assumed my drivers were up to date. I update them by going into device manager and right clicking and selecting Update Drivers. Which has worked before (Tomb Raider did the same crash to desktop immediately thing, which turned out to be an out of date audio driver of all things, which was fixed using this update method). Well, shockingly, using Windows to update drivers, even manually like that, not the most reliable. After fiddling around with some settings in the Nvidia control panel, I got an error telling me my drivers were out of date and exactly which version I needed at minimum to play the game. Download those from geforce.com directly (and download their program to auto update drivers independently of Windows) and voila, functioning game. A few cut scenes are a little laggy here and there, and the load screens take forever (I'm talking a full minute or longer) but the game play itself functions just fine so far. I didn't play past the prologue, so maybe issues will crop up if I play for longer periods, but so far so good.
So the moral of the story is never trust Windows. I'm assuming most people here know better than I do how to properly update drivers (y'all seem way more tech savvy than I am in general). But just in case anyone else updates the same way I was doing prior to this...yeah, check with the manufacturer directly. I was a good 20+ versions out of date.
