First don't drive the car when overheating the 6 is between 90-100 degrees c operating temp and your needle on the cluster will not begin to move until 117 so if it was in the red when u drove it. It was way overheated.
second if u have no issues after bleeding then u r all good if you drive it for a few days or weeks and the same problem occurs my oppinion is that u have a small leak somewhere thus allowing air to slowly enter the system. If problem continues after hoses,radiator,waterpump,ect ect has been checked for leaks. 1.take out thermostate and drill a 1/16 inch hole on the top of the tstat and reinstall 2. Check your head gasket. It might not b showing typical sighns. Ex. Milky oil, burning antifreeze out of exhaust, constantly adding antifreeze. But rather u may have a small leak on the exhaust port on the HG not allowing large amounts of antifreeze into the system but minor amounts. And small amounts of air that build up over weeks or months depending on how often and Lon u drive the car.
Hope this helps