Migration versioning of Active Roles

We're currently on Active Roles version 8.1.3 in a single datacenter with multiple web servers and always on SQL DB.   We're looking to re-architect to a dual datacenter model (keeping our current datacenter as-is).   Question is how to stand up the new servers in the 2 new datacenters and migrate.   The latencies are 8-10 ms.

Our current plan is to attach our new servers in the new datacenters to the existing DB in the existing datacenter, then migrate the DB when we go-live.   One question is application versions.   Can we install 8.1.5 on the new servers?   Or should we stick with 8.1.3 and upgrade later?