I second camping at Horseshoe Meadows on the night of the 27th.
Horseshoe Meadows is currently closed. Does anyone have a suggestion for a good acclimatization campsite if it remains closed?
If you are coming from Northern California, you could always stay somewhere around Tioga Pass (ie Tioga Lake, Saddlebag Lake, or Ellery Lake) or maybe the Rock Creek area. But these campgrounds would be a long ways out of the way if you are coming from Southern California.
But probably the ultimate car camping spot for high altitude acclimation would be the Barcroft Gate area in the White Mountains. This area is at about 11700ft. And you could even get in a little easy hiking at over 12000ft. But for many flatlanders, sleeping at 11700ft your first night out may be a problem. Also, it’s a little out of the way, even if you are coming from Northern California.