FreeNAS Syncthing and Server 2012R2

I am trying to create a backup of our windows file server on FreeNAS-11.2-U4.1 using Syncthing. I am finding no information about how to do this. We have two sites, a hundred miles apart. My plan is to have a windows file server at each site, and a FreeNAS at each site. I am trying to sync from the file server to the freenas at each site to have a backup of each sites data. Once that is working, I plan to either use snapshots of the FreeNAS and push them to the other site for offsite backup, or just sync each sites file server to both of the FreeNAS boxes. We currently have a 50 mb fiber bridge between the two sites, and will be setting up a 400 mb vpn via pfSense in the near future for redundancy and to push the desired traffic where we want it to go. Does anyone out there have experience with this scenario, see problems with it, or have suggestions for a better method. I am new to this forum but have utilized the numerous videos and tutorials from this site. Thank you in advance for your thoughts

You could go Windows File Server <–SyncThing–> FreeNAS <–ZFS Snapshots over VPN–> FreeNAS. While you can use SynthThing for remote syncing of files just fine, ZFS Snapshots will not be off site replicated that way. ZFS Replication between sites will replicate snapshots from the primary server to the backup.

Is it a complex process to restore a windows share with just the snapshots replicated to the offsite FreeNAS? My thoughts for the live sync to FreeNAS (same rack) is to have a share available in the event of a failure on the windows server or server drives and the offsite FreeNAS in the event of a site failure. I am also using Timeline Genie on the windows server for file versioning and point in time just for minimal restores. Is this approach correct, or do you see possible points of failure?

And also, thank you all for the time you put into helping myself and others.