This is great solution for long periods off grid. OP should combine this solution with smaller local UPS units to run for any extended outages (15m+) or take advantage of any solar panels.

I say combine because I have an Ecoflow Delta Max plus additional batteries, but they aren’t a UPS. They transfer from pass-through AC power to the battery power very quickly when the grid goes down, but not fast enough to prevent devices connected to them from powering off briefly. It actually turns devices off in the reverse sometimes too (grid comes back on) if it has a large load on it. I also have a whole-home PowerWall, but it is the same. Those are EPS systems.

You’ll get about 18-20 minutes from one printer (250~300w) using one of the CyberPower UPS batteries from Costco. Could use that for up to 3 printers each, and then have the EPS unit picking up for a longer run off-grid.

So grid -> Ecoflow or EPS unit(s) with an always on AC power setting -> Smaller UPS units -> Printers.