20000, 25000, 30000 (in reality 20 notes, 25 notes, 30 notes).
If there are not enough 1000 Baht notes in the safe you are unlucky.
I know from experience that nowadays you might get more, had 50k from a Kasikorn ATM.
No idea whether they could impose a daily limit on a foreign card.
I think this will be up to your issuing bank.