BitGo provides a mechanism to freeze your wallet if you would like BitGo not to sign transactions for a period of time. To do so, go to your wallet, and then navigate to Settings > Freeze wallet
Click on on the "Freeze wallet" button to freeze your wallet. You will be asked for a 2-factor-authentication token in order to do so.
After freezing your wallet, BitGo will not cosign any transactions for the time period you selected.