Dual WAN ipsec same network

[dochy]

Hello everyone I use pfsense to connect two remote offices by ipsec vpn. Both offices has dual wan for failover and i cant release how to organise ipsec between offices with failover. Here is my schema. Can you help me? Should i create four ipsec for each pfsense?
Wan1 pfsense 1 - Wan1 pfsense 2
Wan2 pfsense 1 - Wan1 pfsense 2
Wan1 pfsense 1 - Wan2 pfsense 2
Wan2 pfsense 1 - Wan2 pfsense 2
I afraid there will be a loop if i configure as higher