Hopefully the reinstall worked out better. When I said everything gets installed to home I didn’t mean literally everything. System level stuff gets installed at root. Personal stuff gets installed on home. Like Steam gets installed on root, Steam games get installed on home.
So you do need enough storage on root for all the system level stuff you might want to do. But the vast majority of your space will be taken up by user-level stuff.
It’s worth noting that you can resize partitions without starting over. You can reduce one partition to move the space to unallocated, then assign the unallocated space to the other partition.
Well anyway, I hope you enjoy Mint despite the rough start. The second partition has proven useful when I tried a different distribution a couple of times. I didn’t lose my local notebooks or ssh keys that I use for development. I’ve repaired my system a couple of times after a hard lock, but if I couldn’t I like knowing I could reinstall to repair it and not lose anything that’s a pain in the butt to deal with.