Thanks for the reply.
Pretty much what I attempted (with lots of backing up original files) whilst waiting - didn’t know how long a reply would be.
Turned out config/config.php had sqlite3 for the DB so was even easier.
I copied the NC Installation directory to where I wanted it. Backed up the config/config.php. Edited the config/config.php to add the new domain to trusted domains. Changed hte data directory to the new one. Changed the overwrite.cli.url.
Tested by going to the <domain_name>/<installation_path> and logged in as normal. Checked files, calendar and contacts etc. Everything there and fine.
Made client and Dav agent changes and everythign seems to be working. Keeping my backups for a few days in case.