If you want to get to Ventura/Santa Barbara from I-40 without going through LA, you could do this:
Take I-15 to Victorville, then CA-18/CA-138/Pearblossom Hwy to CA-14. Take that to the Sand Canyon Rd exit and take Soledad Canyon Rd through Santa Clarita to Magic Mountain Pkwy to I-5. Take that north 1 exit to CA-126. There's plenty of lodging in Victorville and Santa Clarita.