I don't think I have an inbuilt graphics card (or couldn't find how to use it), but I did try rolling back drivers, playing in windowed mode, and really bringing down the resolution. None of that seemed to help.

I eventually got frustrated enough to wipe the drive, reinstall my OS, and download literally everything over again and that seems to be working so far. Always hard to tell with intermittent errors, but I've played for two days, an hour or two each day, with no crashes so far. Here's hoping that resolved it.