Policy Based Routing Failover

[FatalHalt]

Hey guys,

I'd like to set up some policy routes to send only certain traffic over WAN2 instead of the default WAN1. No problems here. In the event that the WAN2 link dies or becomes unavailable, I'd like this traffic to flow out the WAN1. I'd like to use either of them as a failover for the other. 

I'm thinking I need to create default routes for both WAN links, set the WAN2 link to a higher distance so that it only becomes the active default route if WAN1 goes down. I would then create Dead Gateway Detection tests on both interfaces so that I can check for either of them going down.

Does this make sense? Anything I'm missing?