HA across comcast switched fiber network
I have a client with multiple remote sites. All of the remote sites are connected back to the main site via Comcast switched fiber Ethernet with layer 3 static routing and no connection to the internet. The remote sites come back to the main site for internet and all server access, the main site runs a 200D. The plan is to make one of the remotes a hot site and adding a connection to the internet and installing another 200D. Routers between the layer 3 switches and the Comcast link for OSPF routing will be added at all sites. Is it possible to configure the 200D's in HA in the case that the main site goes down?