How to configure eBGP failover between two sites on Cisco?

Question

Cisco

Colleagues, I ask for help in setting up a subject.
Given: two geographically distant data centers. Between which it is planned to configure SRM. Two routers, one per data center. On one (in the redundant data center), DMVPN aggregation was raised over Phase 2. One /27 PA pool (can be converted to PI)
Task: to ensure the availability of services in the backup data center on the same "white" IPs, as well as to transfer the DMVPN aggregation point to the router in the backup data center. When restoring a redundant data center - return everything back.
It is clear to me what to do with DMVPN, but it is not entirely clear what to do with the "transfer" of EXTERNAL IP pools and, in general, the implementation of such a topology.

Answer 1

Isn't anycast bgp easier here? Or give a larger network from one data center, from another data center - give a smaller network

Answer 2

Theoretically, you can convert to PI addresses and leave them the same on both sites. Then your prefixes will be sent to the operator from two places. See how CDN was organized by ivi.