I'm planning to do a 10 day scooter trip in cao bang province in November. I ride a 125cc Vespa in Sydney and have a bike license.
In Vietnam the laws are actually quite strict compared to the rest of Southeast Asia. You need to have a local license in order to be legally allowed to drive, and can only get the temporary local tourist license if you have a residency permit in excess of 3 months.
Sorry for the bad news! 6 months ago