Can I extend my stay in Thailand for 30 days after entering overland from Cambodia?

Hi everyone. Hoping someone here will be able to assist with some answers. We will be arriving in Thailand from Cambodia via the land border. We were planning on staying for 30days and extending another 30. Is this possible via overland crossing or do we need to book a flight instead to do this? We are reading mixed reviews saying that we only get 15days that can be extended to 30? Others are saying that we can get 15 days and still extend as per normal. Has anyone done this recently? Your help wi be greatly appreciated.