If you have separate bank accounts you are likely to have several thousands on one account. You can restrict the maximum amount you can withdraw in a day without visiting the bank personally. It would take a week or so to withdraw all the money and send it to your violent spouse.

The only way this would work is if you couldn't leave the house or call anyone - after all, you'd still have a large chunk of your money left. And if your spouse doesn't allow you to leave after becoming violent, what's to stop them from doing this if your stash was secret?

Also you can tell the bank the transaction was fraudulent and you'll likely get your money back.

This is the moment you use your stash to GTFO