John Paul Cook shows how to use WANem to simulate network latency in a Hyper-V environment:
Access WANem from either SQL Server virtual machine using a case sensitive URL that includes WANem’s IP address. In this example, the URL is http://99.99.99.99/WANem. Inside the SQL Server virtual machines, I set the browser’s start page to the WANem home page. Create a delay of 1000 msec and retest SQL Server to SQL Server connectivity.
It looks like a good way of proving out whether your setup can handle extreme latency before you build it for real.