If you're playing at 1080p I guess I could see that happening. If you can overclock it just a little bit more it should give you all the head room you need
Mess with the distance scaling in settings. if you lower it the cpu will be relieved, also with anti aliasing try to tone that down a bit.
not too much of an issue for me, I rarely play GTA V anymore and end up just driving in the outskirts while listening to music.
Basically what I do in GTA V though I occasionally mess things up and have dem cops chase me in the game.