Yesterday I did my covid extension in Chiang Mai and was stamped to Feb 28th. However I heard officers telling others who I *think* had under consideration stamps that if they renewed dec 15 it was 60 days from then and they were advised to come back closer to the end of the month (every person left unstamped) . So if you can get to the end of Feb now I would advise you to do so now. It will be a lot busier later in the month.