There’s no known way to remotely or automatically power on a Canon EOS 80D after it has fully shut down from power loss. If the camera requires you to cycle the power switch or battery-door state, that behavior is not something EOS Utility can generally override, since the camera must already be awake and detected first.

The practical solution is to prevent the camera from losing power at all. Two workable approaches mentioned are:

• Use an uninterruptible power supply (UPS) on the camera’s AC adapter/DC coupler power source so brief outages don’t shut the camera down.
• Use a dummy-battery coupler powered from a USB power bank that supports pass-through operation, so the bank keeps the camera running during a mains outage.

For unattended long-term timelapse, maintaining continuous power is the realistic fix rather than trying to force an automatic restart after a blackout.