Personally I’d go for as big a UPS as I could afford, but I serve some public-facing stuff from my homelab and I live in an area with outdated infrastructure and occasional ice storms. I currently have a small UPS and have been too tired/overwhelmed to set up automated shutdown yet. It’s not too hard though, I’ve done it before. And even without that in place, my small UPS has kept things going thru a bunch of <10 minute outages.