Hi,
Just in case the nouveau driver does not resume correctly and runs the video card at 100% on resume,
I would try installing the nVidia proprietary drivers first.
Second, I would go in the BIOS (using the DELETE, F10 or F2 keys on boot, depends on computer brand) and checking the power options.
Either changing the S1, S3 / S5 powersaving mode and/or activating "Repost Video on resume" (lesser chance though) in the case the kernel/drivers are not able to handle the wake up process or the current configuraiton.
Good luck!