I'm in the exact situation! While thankful I have an acceptance somewhere, UCSF is my first choice and I'm hoping to not have to deal with multiple deposits...
I've been accepted to both USC programs (declined hybrid), waiting on Samuel Merritt, and interviewing with Sac State later this month. UCSF is best financially and location-wise for me, so we'll see!
For USC residential, they've given me over two months to put down a deposit, but only 10 days for the hybrid. I think you get one or two weeks for UCSF and ten days for SMU. So it's a little all over the place from what I can tell!