Sorry for posting in a somewhat old thread, but I just experienced this exact problem for the first time, and Google took me here.
After spending over half an hour customizing my characters appearance I was stuck in the mountains and couldn't get out, so I had to quit and start over. After the third attempt (the third time going for one of the pre-created faces just to see if that would work - it didn't).
I got around it by setting the graphics to the Low preset before starting a new game. I did not have to restart the game, I just change the settings from the main menu and then clicked "New Game". After I had gotten through the first few minutes of the prologue (that is, just until I was able to save my game), I went back and set the graphics to the highest settings, which really does run nicely on my computer.
I'll probably go clean up my character at the Black Emporium once I get far enough into the game to go there, but this is a pretty stupid bug which really should've been fixed by now.