I don't think it will overfill.
I have one gpu and 2 cpu slots running right now, and the work folder is 280 MB only.
Other parts of the system:
I have a Linux mint on a spare SSD, not much stuff installed. (but I installed BOINC and rosetta@home too, but that does not run right now)
so on my 240GB SSD,
-1GB for boot,
-33 GB for swap (the installer suggested that, but it's rarely used as i have lot of ram. but you will need a few GB of swap minimum)
-206GB partition for filesystem, of which 188 GB free according to one program displaying partitions, (but only 177 gb free according to file browser, I guess due to file system overhead)
(of which 1.5 GB documents and installers, not necessary for a folding rig, plug in a pendrive for that if you need that).
So the system uses ~16.5 GB now at most.
the "disk usage analyzer" says only 12.3 GB used including my documents, (but it gave a warning, that it could not analyze all folders)
(it's a full install of linux mint including a lot of stuff, like media players, browser, email, libreoffice, many GB maybe)
So, in overall, you might be able to go with some cheap 32 GB ssd if you want to. (1GB boot, 1 GB swap, and 30 GB for the system should be okay)
Maybe, by uninstalling a lot of unused stuff, or doing some sort of minimal installation...
(many distros have a lot of suff that won't be used if you are just folding on the machine)
I just looked up, the Ubuntu distro has a minimal installer:
https://www.omgubuntu.co.uk/2018/02/ubu ... all-option
It removes around 80 packages (and related cruft) from the default install, including:
Thunderbird
Transmission
Rhythmbox
LibreOffice (including language pack)
Cheese
Shotwell
‘Example Content’
Okay, so, more details:
sometimes packages are upgraded, system is being used etc, and things may need to be cleaned:
https://itsfoss.com/free-up-space-ubuntu-linux/