Your entry stamp allows you to stay till Dec 3. You can apply for your one year extension 30 days before then. Your visa sticker which gets you into the country, expires Nov 19, if the borders were open, you could do a border bounce before then and receive a stamp for another year, since it is a multi o-a, but since that isn't available, it will simply expire.
If you can get to Australia, you can apply for the multiple entry tv, that gives you the time in country you are looking for and since you will be near Burma you can eadily do the border hops necessary every 60 days.
You can go to a Thai consulate in Laos and get a single entry Non-O and then go to immigration and get a year long extension based on marriage or I think you can apply for a 60 visiting family extension and then a year extension based on marriage.
I have emailed the Thai embassy DC and asked about this situation of people with pre regulation O-A , how will immigration handle it upon arrival, awaiting a response, but that is the MoFA,, the RTImm Police hotline is 1178,,ask them.