Approximate population for the 6 Californias are as follows.
Jefferson: 949,409 (1 CD)
North California: 3,820,438 (5 CD)
Silicon Valley: 6,828,617 (9 CD)
Central California: 4,232,419 (6 CD)
West California: 11,563,717 (16 CD)
South California: 10,890,997 (16 CD)
EDIT: I also challenge the idea Jefferson would be Safe R. Tester-like Democrats could do well there, and if a high-profile Libertarian would ever do well, Jefferson's the place.
Aren't Tester-like populist Democrats and Libertarians for the most part ideological opposites?!?