At 12V, assuming you don’t have too many peripherals, a bare minimum of 1A is enough to power the VIM3, that was basically the reason USB-C PD was implemented… so that we could transfer power at substantially higher voltage to reduce the current it needs to be sent at…
you can check those docs @RDFTKV has given, they show that the connector supports a voltage up to 50v and a current of 1A when using a 30AWG wire…, but I don’t know what is the wire gauge on the VIN cables…