I can only speak for myself on how I'd do this, but I'd dedicate the non-SSD for /home which avoids most of your headaches. For games on your SSD drive you could just make a dedicated /games folder on your root partition.
Personally I'm lucky as I have a 2 TB main SSD (NVMe), so I don't have to choose. And then 2x4TB for storage, backups, linux ISOs etc.
Obviously you don't want "just buy a bigger SSD" answer, but I'd definitely consider saving up for that.