Ask HN: help with relocating to San Francisco

I am relocating from Atlanta to San Francisco. I have a family and we have decided on living in the Walnut Creek area. I have been looking for a room to rent for November and December, while I pave the way (settle in to work, get familiar with the area, schools, etc) for the family to join me in January. Due to the 3000 mile separation, there will be a 2 to 3 week lull between talking to potential roommates and actually seeing the room/house and moving in. How would you go about safely handling security deposits during the time after you've talked to a potential roommate, until it's time to move in the new location? Escrow? Credit cards and chargebacks? Just don't do it and hope it's still available? Other instruments or tools that aren't well know?