Admittedly this is not a huge sample size but anecdotally I think only one or two people were admitted with lower GPAs. I’d say your chances of switching from Math-CS to CS are pretty low so I’d look at math-CS as your main option.
https://docs.goo gle.com/spreadsheets/d/1AwYbPAeHDsOpkrnkyFzVFETqq6xxn3_D55xkFSQ39HI/htmlview