XG to XG IPSEC VPN setup with dual WAN zt each site

Use VTI (Route based VPN) in XGv18. 

It can establish both tunnels at the same time and the routing stack will take over. Use static routing or SD-PBR Routing to do so. 

https://docs.sophos.com/nsg/sophos-firewall/18.0/Help/en-us/webhelp/onlinehelp/nsg/sfos/learningContent/VPNCreateRouteBasedVPN.html

Any thoughts for v17? I played with RED tunnels and static routing, but I can't get failover there. And policy based routing on a RED tunnel doesn't seem to work.

V18 would also solve this limitation on RED. 

So the upgrade would actually be the best case for you. 

So SD-WAN policy routing in v18 supports RED tunnels? Seems like it might be easier to maintain control then with ROute BAsed VPN. I Looked at your reference article, but I don't see how that applies to multiple IPSEC tunnels to/from the same locations. Would it just be multiple tunnels with multiple routing options? Hopefully if a tunnel was down it would remove/skip that policy route in favor of a route that was up and passing traffic.