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There is a key in the config file that identifies the node so you can start it remotely from the cold wallet.
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You obviously don't know what a cold wallet is.
A cold wallet is one in which the private keys are NOT stored on a machine with ANY access to or from ANY other machine at all.
I think the definition of 'cold storage' is somewhat ambiguous, but in general refers to storing keys offline except when it's necessary to use them online, which in the case of masternodes is when you need to start the node - typically following an upgrade.