Wow, I was watching your posts when you and your daughter did your trip!! Thats cool that you were the one to reply too. I've seen your other posts as well on CGOAB. I know you ran out of time on your trip. I hope you can complete the SC route. I really enjoyed reading your journal.
Your right, timing will be important and I have also had thoughts of riding it late summer as well (end of september) As far as the heat goes, I know the area well east of san diego where you ran into the nasty heat. (I grew up in san diego county) and think that palmdale to tehachapie wasnt to pleasant either.
My background in cycling is road racing and mtn bike racing for years so ive trained and raced in many "harsh" conditions from mostly-southern cal to northern cal. Ive always wanted to do a long trip though.
My first trip was only a six day ride from SF to Huntington Beach in 2008 (avg'd 85-90 mi a day or so) with a friend on our road bikes. That trip was pretty much a breeze. We spoiled ourselves and stayed in hotels with our families as they drove ahead to the next day's destination). However, I want to do the SC route on my road bike, then eventually the Great Divide route on my MTB, N to S - thats the ultimate goal.... (now that Im 51). For those trips I plan on camping 75% of the time. Ive started collecting lighteight gear already. More than likely be pulling a BOB since my road bike is carbon. I'm going for a lightweight bikepacking set-up for the MTB.
Thanks for your reply and hope to read more of your journals. Those are memories that you will have with your daughter forever..Good luck on doing the rest of your trip. I also look at Crazyguyonabike.com and bikepacking.net. Thanks, Ken