WAN Failover and Loopback Interface as VPN Endpoint

Hi,

I`m on FortiOS 5.4.4 on witch a Fortigate 60D. Does it work to create a WAN Failover with to different ISPs and using an additional External IP-Address on a Loopback Interface as VPN Endpoint?

I want create two Routes from Loopback through both ISP Interfaces with different Priorities. VPN Connections will use the Loopback as Peer. So I hope, when one ISP is down, VPN still works because the Loopback is now available through the other ISP Interface.

Does ist work like this or not?