Reinstalling archived multisite

Each year, my company runs a multisite install so suppliers can run their own WP sites.
Each year, suppliers ask to see what they did the previous year. Instead of just leaving the site up and running, it gets archived
I’d like to reinstall last year’s content.

I just set up a fresh install of WP network using the same database. All last year’s content is in the database with a wp_ prefix
The new install uses “new_” as a prefix

I also have countless backups of the database.

It *seems* I should be able to just change the DB table prefixes from “new” to “wp” or vice versa. Or should I start over with a new database, with the ‘wp_” prefix, and import the old database dump?

TIA!