@Joanne ***********
; There always HAS been a rule that if a foreign couple are married only ONE needs to meet the proof of funds for the retirement extension and the other spouse can get a matching extension based on being the "trailing spouse" So that's not a new rule or a rule change that's gonna happen next year.
Unfortunately for you and your spouse what you can't do is get a 90 day non-O visa inside the country issued for the reason of being a trailing spouse of someone applying for a 90 day Non-O based on retirement.
You say you need 21 days left on your stamps to apply for the Non-O's so that leads me to believe you're in Chiang Mai <- they are about the only office I know that requires a minimum of 21 days left on a stamp to apply for an in country Non-Imm visa.
IF you're going to get the Non-O's inside the country you're BOTH gonna hafta be over 50 and BOTH meet the financial requirements to get the initial 90 day non-O's.
After you have those you MIGHT <- as in possibly be able to have your husband meet the financial requirements for the year extension (800K baht in a thai bank account in his name only for 2 months before he applies) and you get the trailing spouse extension. I say might, because as a general rule you have to get the first extension on the Non-O visa for the reason it was issued and you'd have a 90 day Non-O issued based on retirement because you met the requirements to get it NOT based on being a trailing spouse. I honestly don't think it'd work but you're out nothing by trying it