partitioning – Ubuntu 18.04 What is the size of the root partition relative to the house?

I'm just asking because I hear how each software installed, especially from the repositories, occupies smaller spaces in the drive. I also know that they are usually installed in / usr paths or elsewhere in the root.

I plan to install between 30 and 50 GB of root partition and the rest of the available space on the home partition of my SSD drive (500 GB). I also plan to format and mount 2 disks (4 TB hard drive and 1 TB SSD) on my Ubuntu system as storage. The hard disk will be symbolically linked to the base directory.

Overall, how much space should I allocate in the root partition compared to the house? I was thinking of 100 GB in case I would install a lot of software, but some of you may say that they are excessive and that a quantity of 20 to 30 years should be enough.

Again, I pose the question because, in some setup configurations I've seen, the entire drive is used for the root partition without the original partition. I admit that I do not find too many questions of this type.