Created with fulgora in mind, give your main island's network one of these and your bots will go and build stuff even in disconnected networks.
This mod will work poorly alone, you'll need a mod that increases robot battery capacity by a whole lot, and there's still nighttime lightning.

Some mods that synergize well with this mod:
- https://mods.factorio.com/mod/construction-robots-use-all-their-energy-to-build
- https://mods.factorio.com/mod/platform-construction-only-no-construction-robots

Similar to this mod, but unlike that one it doesn't force a single global network:
https://mods.factorio.com/mod/roboports-only-required-for-charging

graphics by Hurricane046