I have the same task. My wife wants to see when washing is over. There is no WiFi available in the washing room but I’m able to connect via PowerLine.
At the moment I see only this solution:
TP-LINK TL-WPA8631P + i.e. Gosund EP2 Smart Socket
I already have TP-Link TL-PA7010P and Gosund EP2 so it should fit. But would be nice to know if there is a better (and cheaper) solution.