For those who don’t know, here’s a little trick I’ve been using for a long time:
Windows has a setting that resets your graphics-card driver if it takes longer than a certain amount of time to finish a calculation. Quite often the default value is way too low for Blender/Cycles GPU rendering, and this causes a lot of crashes in scenes that would otherwise render fine, even on very fast PCs.
This should work at least on Windows 7 and up.
More detailed info: