What are my options for visa extension in Thailand before relocating to the US?

I believe you can go well in advance. I'd go on September to cancel and immediately apply for the Covid extension

You would go cancel the extension you're on now with the documentation you have (BEFORE the 27th). They'll cancel the extension and give you a new stamp letting you stay until the termination date. You should be able to apply for the 60 day covid extension right after you cancel the extension.

ASSUMING YOU HAVE NOT ACQUIRED A 60 day extension of stay based on visiting Thai family .et.

On October 2nd, when your one year extension of stay baed on employment is over, you will cancel your one year extension of stay based on employment, and get a 60 day extension of stay based on visiting Thai Family. You will need the following:

1. Your passport and a copy of:

- Your data ("picture") page

- Your Non-O visa

- Your entry stamp

- Your departure card

2. Your wife PHYSICALLY next to you, and

- Her ID card and a copy of her ID card

- Her housebook, and a copy of the first page

3. Marriage certificate (either the rose border certificate, OR a translated copy from your home country)

4. The application form

5. 2x passport pictures

6. 1,900 THB for the processing fee.

Different immigration offices have different requirements, and this may include:

- A copy of the TM30 filed where you live

Did you already get a 60 day extension of stay based on visiting Thai family yet?