How are you paying for the OOS schools? Did you get a full ride? Did your parents leave you a college fund? If not, where’s the money coming from? You can only borrow $5500/year. If you’re considered an independent student for financial aid, you may qualify for full Pell (about $5k/year), but I don’t know of any aid that pays all costs for an OOS student at a CA school. Oregon & WA I don’t know about.
I’d make sure the schools you’re accepted to are definitely affordable before breaking the news to your grandma.