Can I renew my Non-Imm O (marriage) extension at Rayong Immigration earlier than the expiration date?

I believe in Rayong you can apply for a new yearly extension when you have 30 days or less left on your current stamp.

OR

you MIGHT get everything together as far as all the documentation, bank letter, bank book, etc AND your proof of your flight out before your extension and won't be back until it expires

They MIGHT <- as in it is possible they'll let you get the year extension early because of those circumstances, OR they'll say nope just let it run out and start all over again when you come back

In that case I'd just let it run out, get a new 90 day Non-O visa based on marriage from the thai consulate when you go home, come back and then apply for the year extension.

Those are pretty much your options,

AND sadly even though the office is far from where you are, that stamp is all that lets you stay here so I'd slog on over with your thai wife and hash out what can be done. OR go with the "get a new Non-O and come back" option