Maybe you can have a Dual router with a single ISP peering for redundancy (some example, not cover all but you get the idea)
https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/13762-40.html
Note: do you have a redundant path for the ISP, if the link fails? if you have only 1 Link - may not be optimal, but you have local device redundancy.