To add to Shawn's spot on comments regarding travel time and conditions, I'd just have to say, I hope he's (your friend) really on good terms with his relatives and that they like to drive.
If I lived up there, fresno and thereabouts, I'd probably not give it a lot of thought––but driving from San Francisco, all the way down to Fresno and then up and back and in and then possibly out again, same day, well . . . .
Add at least four hours for the drive just from SF to Fresno, just to be safe
I'd suggest that maybe you book them a room at the VVR or maybe Mono Hot Springs, or at least, take advantage of the experience of the slithery fine pools of water there at Mono Hot Springs.
It also doesn't hurt to use your horn and stay way to the right when you get out there in the backcountry as there are often some "road rally" drivers out there. ( I only had one head-on ) . . . lotsa young kids like to drive up to Mono Hot Springs area.
And just a note . . . there are probably a few spots--times--conditions when car clearance and four wheel drive might be of value, like early spring . . . I wouldn't want to drive back there in a souped-up ground hugging roadster, but you can pretty much get anything all the way back to VVR, as long as you are patient and don't mind a few sections of washboard road.
However, should you get up the there and have the sudden urge to take the turn off and drive out to the Bear Creek Diversion Dam, you better be ready for some high clearance four-wheel-driving.
I would also suggest that your buddy take the Bear Creek Cut-off Trail.