It depends on your tolerance for twisty roads. I love 395 and the back side of the sierra, but to get to Yosemite, you have to take 395 to 120 west over a 10,000 foot pass and then down a long twisty to get to the valley. Just did this in a 35 foot towing a Jeep. Wife never wants to do it again. Beautiful views but very few places to stop in an RV and look around. The other fun thing about this road is that you have a lot people driving up on the cliff side who are intimidated by all of the down and crowd the center line.
The alternative is 58 to 99 to 41 and 41 is no piece of cake. Forget 140 unless you want to unhook because of length restrictions on the temporay bridge. I live off of 41 a ways below Oakhurst and after Oakhurst, it does get twisty.
For either choice, it is a wonderful place and not to be missed.
As a side issue, no hookups in the valley.
2001 Winnebago Adventurer, 35U, W-20 8.1
F+R Trac bars, F+R sway bars, SafTsteer, F Sumo Springs, 4 Koni FSDs