I think you would have to mount the temp sensor on engine and wire in a separate light or the car could have the original warning light. I have mech oil guage and kept the idiot low press light also. In industrial engines they used a "switchgauge" that would kill the engine if low oil pressure or high water temp.
Mopar has a combination water temperature sensor that had both a gauge and an warning light hookup. Just have to run a wire for and install an indicator light in adddition to your gauge setup.