Try this & see if this helps
An offline replication can be configured in this type of scenario so that when configuring replication on the target server does not replicate a huge amount of data via wan. The steps to configure the same are…
1. Arrange a server on the same remote site local network with the same server name as the main target server. IP address can be different.
2. Install SEPM on the server and configure it as a replication partner with the target remote server which is in the same local network with the same site name as the actual target server.
3. This replication should succeed as both the servers are in the same local network.
4. After initial replication configuration is done configure the replication partner properties and do not enable logs, content and client packages replication.
5. Initiate manual replication 2-3 times to ensure it is working as expected.
6. Take a backup of the new server DB and server certificates and key store password. Follow the disaster recovery Document to perform the same.
7. Make sure that you have most updated server certificate. To ensure take a backup of the certificate from SEPM. (Admin-Server-Manage Server Certificate-Backup the Server Certificate)
8. Transfer the whole backup to the target main server.
9. Shutdown the new server created.
10. Install SEPM on the main target server as a standalone site with the same site name.
11. Restore the database following the disaster recovery document and reconfigure the management server.
12. After the reconfiguration is complete log on to SEPM and restore the server certificate.
13. Ensure the replication configuration and Replication management server list reflecting correct settings.
14. The replication should work fine now. Ensure the same by initiating a manual replication.
15. Schedule the replication.
16. Decommission the new server that was created earlier.