@Louis *******
IF they are willing to sell you the in-country Non-O visa based on marriage (not all immigration offices sell in-country visas), and you meet the qualifications, including the time remaining on your current "admitted to" stamp, you should be able to get the visa and the resulting extension of stay.
Surat Thani has a website at
Surat Thani Immigration Office Website:
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you can contact them directly and see what they say.