So I'm looking for anyone who has done the extension based on marriage recently in Chiang Mai. Last year when I did my first extension based on marriage at the mall as far as finances all I needed was the affidavit from the US Consulate here in Chiang Mai. Does this still hold true or do I need to provide something else because my money is tied up in the US , so I can't show 40,000 baht a month even though I make the money that they want per month, I can't show it in a bank statement because it's tied up each month in the US.

So long story short my question is can I in December when my non-O based on marriage visa extension comes up for renewal for another year ,can I use the financial affidavit form from the US Consulate like I did last year?

Yes.

Yes, as long as it’s a new one dated within 6 months.

They, CM IO's have had a practice to question it before. I used one years and years ago and was told real proof would be required the next time. I would honestly say 50/50, so take your chances and now you won't go into the interview with head strong feeling it is automatic when it isn't. Age of the person also will play a role with the IO's discrepancy. 

Some people have had required to show more proof in addition to the letter.  Here is a link.