Boot from live CD/USB, dd from "Hp SSD 800GB raid 0" to "Nvme 1TB raid 4", shutdown server.
Disconnect or remove "Hp SSD 800GB raid 0", power on, goto BIOS setup and set boot from "Nvme 1TB raid 4"
Try to boot Proxmox from "Nvme 1TB raid 4"
If all ok, reboot from live CD/USB and grow data volume.
But, safest way - what Wolfgang said.
Backup all VMs, backup pve settings, reinstall Proxmox VE on new disk, configure it and restore VMs.