OP, suggest you ignore some advice in thread of wife using ATM after death.
If you are only concerned about the 800k going to wife/partner then you could consider changing to income method.
I transfer 120k each month and as soon as it hits funds then transferred into partners account.
If it's more than the funds in the bank eg cars, condo etc then 100% make a Thai Will.
If married check with your bank if wife can be added as "silent signatory" to the account.
I know it's possible however check with bank if this is an option.
BTW: you can set much higher ATM limit. Even higher if ATM transfer to another account (same bank)
K Debit Card: Withdraw up to 200,000 Baht per day, transfer up to 1,000,000 Baht per day, and purchase up to 500,000 Baht per day at VISA stores
K Max+ Debit Card: Withdraw up to 200,000 Baht per day, transfer up to 1,000,000 Baht per day, and purchase up to 500,000 Baht per day at VISA stores
Cardless Withdrawal: Withdraw up to 30,000 Baht per transaction and up to 500,000 Baht per day
K-ATM Transfers: Transfer up to 200,000 Baht per day to a KBank or interbank account
Kasikornbank also offers a K-Express Cash card that allows up to 10 withdrawals per day with no fees