If coolant temp sensor goes bad, you collant temp gauge will be inop, but the engine management should spot this and go over to a pre programmed map according to run time, as it knows how quick the car should warm up.
Won't be perfect, but should keeps things running with very little ill effect.
Thats how it should work from a cold start anyway, not sure what happens if it suddenly dies.
The figure quoted sounds like default reading, so could be open circuit to sensor, ecu, or something else!
Did they mention the ecu wiring harness issue? it may have only affected RHD vehicles.