SQL alwayson on Availability Group

Need advise on below:

I have 2 node alwayson AG on Primary Sync mode in the current configuration and fsw is in Primary DC only
Actually during Switchover the entire DC 2 node and fsw will be down
Which DR configuration should I opt in this situation for little manual steps and DR can come up without much issues:
2 Node Async in DR
1 Node Async in DR

I am using SQL 2012 Enterprise, Windows2012 OS

Have 2 nodes in the DR site in Async commit mode.
Put the fileshare on 3rd site.