Why not just put a single 2 TB partition on the drive and install Linux to that, and then make a partition, or multiple partitions after you install Debian.
Other options include setting up the Linux Logical Volume Manager (LVM), then creating multiple volumes for your file systems. You could also use a single BTRFS partition and create subvolumes, which is how one of my machines is currently configured.
You didn't mention whether you were installing from the command line or using the Debian installer; I don't know which options the installer supports these days, as I haven't installed Debian in more than a decade, other than on a virtual machine running on an Arch Linux host, and I had a prepared image in that case.