How much power does just the NAS use?

the NAS is the bulk of the 100W.

Are you running something like Unraid or TrueNAS, or are you just running a ‘regular’ Linux distro?

Ubuntu + ZFS. I don’t see the appeal of running a non-mainline distribution. All I did was set it up so ZFS sends me emails and a crontab to run a ZFS resilver weekly.