Sounds like a great trip.
Depending on how early you get to Dry Lake, you can summit San G and back in one day (also depending on your fitness level). It’s a long day, though, but it’s exactly what I did my first trip up there.
I got to Dry Lake about 12:00, set up camp, had a snack and felt pretty good so I headed up. I think it took me 4 hours to get to the summit. Walked almost the whole way back in the dark. Luckily, I had brought along my jacket and a headlamp. 🙂 Not to mention, I used my GPS track to find my tent in the dark!
Your plan of camping at Dry Lake and summiting in the AM is a good one. An option, if it suits you, is to leave VERY early in the AM and get to San G for the sunrise. But realize you’ll be walking an unfamiliar trail in the dark at first. Otherwise, wake up, have a good breakfast and head up. You’ll have all day at that point. Take your time and enjoy the views.
It’s about 5 miles from Dry Lake to the San G summit. Being at altitude, it may feel like a very long 5 miles.
You can leave your camp all set up at Dry Lake. Put any food/ scented items in a hanging bear bag or bear can to be safe- from both regular bears and “mini” bears (squirrels etc)
While I’ve never heard of problems of theft, I would also recommend taking your car keys, wallet etc with you… and any gear you might need should you have issues on the trail.
Have a good time!