But it is funny that this one fills up when it is HUGE and there are other options in central CA.
I'd asses the reality of congested Central Valley travel in the exact opposite manner. Granted I only have a data point of one (today), but Gilroy, Gustine, Fresno, Harris, Kettleman, Bakersfield, Buttonwillow, and Tejon were all hovering in the 0-3 available stall range for hours during peak *sugar* show. I charged at Casa de Fruita on the way out of the bay and that was even abnormally full with ~8-10 stalls occupied.
Anyway, I would surmise that, if Kettleman is full, you absolutely WANT to go to Kettleman unless you're really fixin to gamble on one of the other locations. The 10 car line moved at more or less a car per minute, and by virtue of the statistics of 20 pairs, you're VERY likely to get a good paired rate. I was paired with a 100D and started off at something like 90kw. A 1-2 car wait at one of the smaller sites could easily be 10+ minutes, and even if you luck out and get an open plug you're more likely to get a crappy initial rate.
For the record it was so crowded that nav routed me down 33 out of KC, with a cross back to the 5 on 46. I actually kept going to Maricopa and it only added 10 more min drive time...and easily double that on my lifespan.
No traffic...cruise at 68 the whole time.
Note: Should you find yourself that way during the day feel free to take some juxtaposed photos of your Tesla in the endless fields of derricks...