The last post from Josephbloggs is correct matching my knowledge.
however most embassies need the evisa system and you will have to go outside for 7 to 10 days.
Some places outside do not need the 400 k for the first non-o ninety days, but you will need to search.
I did the simplest thing, go out and get visa exempt. its 60 days. then apply here for the first ninety day.
However, to do that you will need the 400k in the bank the length required.
If you get the 400 k transferred quickly now, you may be able to plan going out and apply when you come back in. You say you have 6 weeks, presume you have to get out then.
You need to read the posts below that also concern what to do at work permit expiry.
If you go out in 6 weeks, and get 60 days visa exempt on return. You could meet the 400k time period.
Be aware that getting the first 90 day here needs alot of paperwork and can take 3 to 4 weeks from the application. I am still waiting after 3 weeks (but that did include songkran.)
I posted the marriage visa checklists from Chaeng Wattana and Hua hin in the post justr below.
https://aseannow.com/topic/1352010-simple-question-for-this-idiot-about-non-o-marriage-multi-entry/#comment-19596444
The other recent posts to read are
https://aseannow.com/topic/1357404-my-situation-can-i-beat-the-system-of-a-marriage-visa/#comment-19726305
https://aseannow.com/topic/1355113-visa-options-after-work-permit-cancellation/page/2/#comment-19726377
https://aseannow.com/topic/1352405-non-imm-o-marriage-vs-retirement-based/#comment-19605957