I can tell you that my Celeron J4105 (the N100’s predecessor) can run paperless and most other NAS/home server tasks just fine. I haven’t dabbled with Immich and its ML though. The 10W are pretty accurate. With hard drives, HBAs and PSU inefficiency, my home server comes out to about 20W from the wall under full load IIRC.
Also look out for RAM extensibility; you probably want 32GB in the not too distant future.