If you're open to going north, you'll extend your hiking window weather-wise. You'll clear the highest points in the Sierra early on before any early snow can reach you.
Just one word of warning going north during August and September, - and I can not over-emphasize this point - it is a DANGEROUSLY hot, dry, and often exposed walk from Highway 58 all the way to Chimney Creek campground south of Kennedy Meadows south. There is not a lot of shade and only a few reliable water sources, so plan accordingly.
A lot of folks under-estimate this stretch and that keeps SAR busy. You will probably want to get up before sunrise, hike steadily until 11 or 12, then find a shady spot (such as there is around those thorny Joshua trees) to rest and sleep until 5 or 6 pm before continuing until sundown, or later. Eat your hot meal for lunch as it may well be dark when you stop for the night.
Consider carrying a good sunshield that you can rig up overhead . I used one of those aluminized blankets - the 12 oz solid ones with grommets and aluminum on one side and orange (also comes in blue) nylon on the other. REI carries them, as do most outdoor stores. Forget those flimsy single use mylar space blankets. I tried my umbrella for walking but the winds were too strong and ripped the fabric off. You will want a good insulating pad - preferably CCF rather than an inflatable (due to the thorns lying about) - between you and that hot sand. I carried a full length Ridgerest until Kennedy Meadows for this reason, then used an inflatable from there on to Canada.
Since you are doing what is essentially a series of long multi-section hikes. you might want to consider entry/exit points with good public transportation options. that's why I suggested Echo Lake, and Highway 58 (go to either Tehachapi or Mojave). There is reliable bus service all along highway 395 from Lone Pine to Reno so you can also get in and out at Lone Pine, Independence, and Mammoth Lakes with ease. The YARTS buses run between Mammoth Lakes and Tuolumne Meadows and Yosemite Valley daily.
Having family vehicular support in northern CA is a big plus; it also saves you the car rental to set the cache. Better yet - no cache. Ask the family to meet you at the day use only picnic grounds at Sonora Pass. It is really nice so they'll have a nice spot - lots of shade, potable water, picnic tables and trash cans, and bathrooms - to wait for your arrival. The PCT runs right through the place so it would be hard to miss each other. They could also run you down to KM north for a meal and perhaps a fast shower, maybe even a real bed for the night if they get a cabin there. Then it's back to the trail and on south to Yosemite or north to Echo Summit.
Vehicular support makes northern CA much easier. There is no public transportation at Sonora City, Belden, or Old Station, and you have to go about 9 miles off-trail to Burney to catch bus service to Redding. Amtrak stops in Dunsmuir (at 5 am) but Greyhound long ago eliminated its stops there and in Yreka. Spotty local bus service connects Seiad Valley to Yreka and Etna.