@Dennis *******
you are stamped in for 180 days each entry into Thailand.
That can be extended 180 days at your local Thai Immigration office. The fee and requirements for the 180 day extension are unknown at this time. The usual fee for any extension is 1,900 Thai baht. But there's Reports that the fee may be 10,000 Thai baht.
You can do a BORDER BOUNCE by land or air reentry and be stamped in for 180 days.