This was re your "IPv6 is inevitable" comment -- we can get pretty far with IPv4. In particular, as long as you keep using third-party load balancers, you could

This was re your "IPv6 is inevitable" comment -- we can get pretty far with IPv4. In particular, as long as you keep using third-party load balancers, you could probably keep using it for decades. And you may never have to migrate your internal infrastructure at all.