2TB. I did this several years ago, and have two still running in my house.
You have to keep the partitions under 1.0TiB. You need to start with an image with a single partition pair, manually create and add partitions without exceeding 1.0TiB partition size.
I've been running them for either 2 or 3 years like that (one is on an AF drive as well) with no problems. The UI gets sluggish as the MFS fills. With SD only, it's got about 1800 shows on it. Past *deleting binges* have shown me getting the number of shows below 1000 or so shows a notceable improvement in responsiveness.
They still run, but have a random reboot on an occurrence frequency of once, to sometimes twice, per week. I'm not certain if it's related to the drive size or not, as their are too many variables. My units have hacks running on them, they are aged units with untouched power supplies, the software on these units was never incredibly stable even in unmodified form, and I suspect, for what they set out to do at the time, the hardware is substantially underpowered.
Can you touch your ____ with your ___? Then go ____ yourself?
The answers are (shoulders, hands, hug). If you came up with something else, that's on you