Thanks for your replies everybody.
It seems the goalposts are continually shifting. I hear that the PCR test will be changed to an antingen from either the 16th or 1st December but the hotel we booked on arrival on Bangkok is constantly asking me to book a PCR through them with a total cost of 12,000 THB!
Obviously we are grateful and appreciative to get into Thailand but I'm a little dubious about this hotel...which had to be booked to get the test and go approval/QR code