Configuring CDN in W3 Total Cache when migrating a website

We have a CDN with MaxCDN for our website and it is configured via W3 Total Cache. We are creating a new website but hoping to use the same CDN since it has a couple of gigs worth of media files for all the posts used on the site.

On the new website install I went to configure CDN in W3 Total Cache, validated with the same key but then it only gave the option to create a new default zone. I was hoping I could select the existing zone we created for use with the live site?

Is there a better or more efficient approach we can take to getting the same CDN setup on the new site that the live site is using?