If your are a shareholder at your local power provider… Or just recicle some hardware lying around any PC, laptop ou small form factor would do the job without a portion of the noise or power consumption, just a guy that runs a similar setup once a week as a redundant backup.

I use an OpenVPN/wireguard servers running on a Rpi3 behind the firewall, once inside the network WOL works pretty good.

Could you use WOL for that?