its pretty unlikely that borders will open (not impossible} by December 4th. Go to immigration (with your wife) and see if they can help you figure out a strategy. Basically you're going to need that money in the bank for a full 2 months Then you can apply for an extension of stay based on marriage. Best of luck.
Best thing to do is pop in to your local immigration and ask them for the handout and follow that closely. You will need two copies of EVERYTHING (notice i put that in capitals) You will also need
*****
0thb in your thai bank account in your name only for minimum 2 months prior to applying.
Make sure you get the printout of your requirements from YOUR immigration office. Follow it thoroughly. In Samui I needed 2 copies of EVERYTHING (so two files) check your landlord has done the tm 30 AND har the screenshot. Won't hurt to take your file in a few days early and get them to look through it.