Disable notifications during DB copy down

We are planning to upgrade to v 12 here soon. Part of our process is to copy content from prod db to test db to get the prod configuration into test in order to accurately and fully test the new version in the test environment before upgrading the production environment. We will be running a PII scrubbing script on the db to remove email addresses, usernames, profile photos, etc. so that PII from prod is not stored in test. 

What I'm curious about is with the notifications settings, are those stored in the db and can we update them to keep notifications off when we bring the test environment back up after copy down? The root of the problem is that we want to ensure that no emails are sent from the test environment to any prod email, but when we bring the test environment down we won't have access to the admin panel.