I'm not Powerline Support but I have a similar property (3 floors). Router on ground floor, 2 upper floors on separate fuses.
Powerline connectivity is possible to separate rings, through the fuse board but Performance is poor, am checking now & why.
I have Powerline PA4020P and PA511s. I need to run some checks to see if this is related to Rings, Fuseboard or Powerlines.
In the meantime, wireless connectivity I my best option.

Hi again., below the results of my tests;

UK Double socket(MK), TL-PA4020P capable of 500Mbps one each plugged into the double outlet, throughput measured at 366Mbps, same socket!
Same Ring, different sockets, 166Mbps. Different RIngs (ground and upper floors), 9Mbps

I chatted online with TP-Link technical support.They reckon this is due to the quality of my home's wiring. Powerline extenders should not be positioned on different rings using the fuse box as a "bridge".
Wireless network to devices on the upper floors are between 43 & 78Mbps.

IMHO, Powerline extenders are restricted to the same ring/fuse. If you try and extend to different rings, performance is rubbish, probably not worth the expense.

Good Luck.