I've been that way a couple of times, and Saltydog is correct. You should consider heading to what I refer to as the 11.2k meadow @ 36.713730,-118.368608. It's approx 2 more miles past the Center basin drainage - this is what it looks like:



11.2k is 14 miles from the Onion TH, so rather than spend the night by your car, you might consider either hiking the 2.5 miles to Flower, or if you're feeling good, go over the pass to the Kearsarge lakes. Not only is 11.2k a great view location, but it puts you 2.6 miles under Forester. If you start around 6am, you will be able to hit the first snow patches before 7-8am the next day, so you can skedaddle over any remaining snow before postholing hell begins. Most of the snow will be gone on the north side, but there probably will still be small sections like this from early June a few years ago:



Tyndall is 7.5 miles from the 11.2k meadow, or 9.5 miles from Center basin. If you did spend the night @ 11.2, you could continue on for another 4 more miles to the PCT @ Wright creek. This is what the Wright creek meadow looks like just 400-800 yards north of the PCT @ 36.603977,-118.369552



One last thing: like Anvil camp on the Shepherd pass trail, no one stays @ Trail camp on the descent (ie way out) if they've got any energy left. Including the r/t to the peak, TC is 9 miles from Guitar. All you gotta do is suck it up and march the last 6.1 miles to the Portal to get a cold beer & luscious hamburger.

Say you leave Guitar by 6am - even going slow & accounting for hanging out at the summit, you'd be @ TC by 2pm. Now, imagine hiking fast (aka 'jogging') @ around 3mph to get down the trail and out; the hunger becomes strong.

PS Be sure to take extra water from Guitar, drop your pack @ the junction, take a day back (a sleeping bag stuff sack with sewn on single strap to sling across your shoulder/back works great - just shove your loose bag into your main pack until you get back) with food*, water & fleece and you're golden.

*Unless you have a bear can, don't leave food in your main pack. The marmots will drill a hole right through it to get at any tasty salty snacks. Upon second thought, you of course will have a can because the Rae lakes area (Forester to Kearsarge to Woods crk) is a *must carry* zone:

http://www.nps.gov/seki/planyourvisit/canister-areas.htm

No wiggling out of that language. As an aside, one of the reasons Shepherd is a favorite of mine & others as a fast-track way into SEKI is because it falls within the 'highly recommended' zone. In other words, you can get away with an S29:

http://www.nps.gov/seki/planyourvisit/bear_bc.htm