1. On your server, you could use "WP STAGING PRO"
Where is the staging site located?
You can copy the staging site to a sub folder of your main site or to a complete custom path. It stays entirely on your server and none of your data will be transfered to any third parties. You can clone the production site to another database and even to the same database of the live site. In that case, all staging site database tables will be prefixed by wpstg_. This ensures that the live WordPress site never interferes with the staging site.
2. For offloading to a different server (60+ GB Website), we use Blogvault
Want to test new plugins or do you simply want to resolve nagging issues. Learn how to set up a WordPress staging site with this guide.
blogvault.net