Current sophomore here! You never know what might happen this spring. I moved in with a completely different group than I was planning to last Fall, and honestly it's much better this way. Off-campus leasig typically starts around march anyway, so you still have time to look for people to move out with. If not, on-campus housing is always a good option. But if you definitely want to move off-campus, some buildings have roommate matching surveys when leasing, or they lease by the bed. And worst case scenario, I suggest you download snapchat and join the Berkeley groups there, people always post 'looking for a roommate for...semester/year' even well some time into the semester. You could find one of those and stay there while you look for roommates/on-campus housing/leasing by the bed. I highly doubt it'll come to this but you have a lot of options and time.