3 Node DAG in same site

Hi team,

There is a DAG with 2 nodes at this moment in the primary HO location. Right now the client is thinking about Installing a 3rd node within the HO Physical location hoping to move it to a Physical DR location at a later time.

However my main concern here is what would be the most preferred method:

1. Keep 3 nodes in the same AD Site?
2. Keep 2 nodes in HO AD Site and one in another AD Site(DR)

What would be the recovering methods of the above? 

Cheers,
Jude