Having done a few too-long trips with pre-teen kids, I strongly, strongly recommend against a "drive and drive" vacation. If I had life to live over again, I would have taken shorter trips with my kids, with much more "outside time" for them than "car time."
Anyway, here are some suggestions:
From the Bay Area, I would suggest the first night in southern Oregon, then a couple of nights at Crater Lake.
After that, maybe Mt. Hood for a couple of days.
After that, Rainier for a few days.
On the way back home, maybe a few days in the Redwoods north of Eureka.
That is still about 2000 miles of driving round trip from the Bay Area -- still very ambitious -- but not impossible.