If your 30 day visa exempt stamp expires on the 21st, you can ask for a 30 day extension of stay based on tourism. You will need the following documents:
1. Your passport and:
a. a copy of your data ("picture") page
b. a copy of your most recent visa (if you have one)
c. a copy of your most recent stamp
d. a copy of your departure card
2. [Might not be asked at Bangkok Immigration] A TM30, filed in the immigration office.
3. The forms (each immigration office may have different forms, and want to use their special forms). For Bangkok Immigration, the forms are found in the FILES section of this group
They did you a VERY solid favor. A person can only get ONE 60 day extension of stay based on visiting Thai family per entry. A person can get unlimited 60 day extension of stays based on unable to travel due to COVID-19.
>I'd like to get another 30 days if it's available to me
Your immigration office granted you a 60 day extension of stay based on unable to travel due to COVID-19 BEFORE they issued you a 30 day extension of stay based on tourism. All Americans can apply for a 30 day extension of stay based on tourism, which will be granted. The last day you can apply for this extension of stay is March 7, 2022 (March 6 is a Sunday).
If the 60 day extension of stay based on unable to travel due to COVID-19 is extended again, I expect you'd be able to get another 60 day extension.
> Figured I'd deposit the 800k and apply before I leave then come back when visa approved after the 60 days sometime
You entered on a 30 day visa exempt. There is *NO* seasoning requirements to get an *In-Country* 90 day Non-O visa based on retirement (assuming your immigration office sells those visas). I recommend moving the 800K THB in a Thai Bank Account, and around mid-February apply for an in-Country Non-O Visa Based on Retirement. You will need some time remaining on your "admitted to" stamp, and I don't know how much time is required for Korat.
After you receive the in-country Non-O visa, you can then apply for a one year extension of stay based on retirement. This extension of stay can be applied any time after you have 45 days or less (30 days or less at some immigration offices) on your current stamp. Ask your immigration office for specific information.
That is a 60 day extension of stay based on unable to travel due to COVID-19 😮 AND... it was added on to your existing "admitted to" stamp. Unusual to see it stamped like that, but it's what you got.