Yosemite/Tuolumne Meadow for RV??

We are staying in Yosemite valley this summer in our 27 foot long fifth wheel and I'm thinking about extending my stay with a few nights in the Tuolumne meadows campground. Do any of you have any experience camping there with a 5er?? I'm only looking at the spots that they say can hold an rv up to 35 feet.(In the A and B loop) I love Yosemite and would really like to look up at the stars late at night in the middle of the meadow. Another issue is that we check out of the valley on July 3 and T.M.campground doesn't say they open until July 12. With the little snow fall this year, I'm hoping they may open early. Is this unlikely? What do you think? Any experience?
Thanks! Lee