For gaming how many games do you have? And how many of them are AAA titles requiring huge amount of diskspace?
From my games:
BF1 and BFV are both using more than 80 GB
BF4 uses 68 GB
Doom again uses 68 GB.
Probably there are games using more than that (Red Dead Redemption 2 or GTA V? I don't have them so I don't have any idea)
Simply 256 GB SSD is enough only one or two such games.
I don't know your gaming preferences, but other than 1 TB SSD, I have 2 TB of games in another harddisk.