The ethernet is for communicating with my domotica and NTP.
I have seen that there is a PoE Arduino, but then I'm missing the battery backup and the USB charge port (not really required).
Extra's I will connect to it:
Rotary button
Color OLED
Buzzer (normally we should wake up with dimming light and sound using the OpenHab domotica communication, but a battery and the buzzer are a backups)
The newest is the Leonardo Eth, which is already, you guessed it... RETIRED!
I recommend just using an Ethernet shield or module with a regular Arduino board. The Arduino Ethernet Shield 2 is not retired but it is sold out in the Arduino store. You might be able to find one from an Arduino distributor or there are plenty of Ethernet shields available which are not manufactured by Arduino. Just be sure to get one with the W5100, W5200, or W5500 Ethernet controller chip, not the ENC28J60.
Arduino boards aren't very good for low power but you can make a few modifications and solve that problem or just design your own board without the components that waste power.