SoCal to east side of North Cascades: 395 or 395/97?

Steve, thanks for the camping tips! Usually, though, when we are trying to make mileage on a trip, we stay in RV parks for the ease and convenience. We save the boondocking for the destination, when we can really appreciate the silence and isolation.

But on this trip, it looks like there are very few RV parks along the way, unlike the west side of the Cascades. So we may be forced to find real camping out in eastern Oregon and Washington.