Sorry but do you mean nodes or clusters? Anyway at this scale you are definitely looking into managed services from cloud providers or using Kubernetes. 1 and 2

Sorry but do you mean nodes or clusters? Anyway at this scale you are definitely looking into managed services from cloud providers or using Kubernetes. 1 and 2 is not an option because of the maintenance burden. Rolling out upgrades and resource allocation is going to be very hard without Kubernetes.