Nobo flip flop with a Mid July start - consider starting somewhere between S. Lk Tahoe and say…Castella. July 15th I was at Donner Pass heading NOBO in 06 - probably about in the middle of the crowd at that point.
Castella / Dunsmuir / Mt. Shasta City has a certain advantage of a NOBO flip start point in that its ON I-5, so getting back there via bus should be pretty straight forward (and its not too far from the airport in Redding). Donner Pass can be a good point as well as Reno isn’t far away (or head up I-80 from Sacramento). I suggest travel logistics should point you to your start point.
Suge nails it in that you’ll have to light the afterburners to beat the fall snow in the Sierra. The upside of a straight SOBO (if you can handle, or in fact thrive on the alone time) is that there is no competing interests of your hiking buddies to slow down for an extra town zero, or match pace with them, etc. Town stops and zeros are all business - get in, get chores done, get out and get hiking again.
Token Civilian