I’m sure it will be fine , most are glad to have tenants anyway , so it would really be in their interest to be too rigid , especially under your explained circumstances ..
For a few weeks ? And you pay monthly direct to your landlord, and not via an estate agent ? .. you can just set it up to transfer to either , or as it’s only a few weeks maybe just ask them that you’re be a couple weeks late .. as long as you pay within the month I’m sure it won’t be an issue ?
You will be fined 500 bhat per day for overstay .. it’s no problem and no issue , unfortunately years ago I did it many times , 2-3 , and a couple of times 5 days … infact once they told me I’d overstayed by 2 days , and never even fined me ! .. that all was years ago , but my understanding ( I live here now ) is that they are quite happy , as long as your not taking the pi** ..
About 5-6 years ago I moved out of mine 35k deposit.. there was a leather chair I never even looked at it was left in a closet for the 3 years I was there ..they said it had dilapidated because it hasn’t seen any light ! .. lost 3500 of my deposit 🙄
They will be quite happy to fine you 2000 bht , don’t worry they won’t threaten to deport you , I think they welcome the odd fine , missed mine once about 5-6 years ago , “ I’m so sorry “ etc , no problem 2000 please 😉