basecamp - network nerding
Tested Wookey's TP-link 200 Mbps HomePlug devices between potato hut & mains socket above the washing machine in the gents' toilet at the Gasthof. It works: the 2nd green light lights up indicating communications OK.
Previously had tested between potato hut mains and socket in potato hut loft - also worked.
To do: repeat test with a laptop at each end (needs ethernet socket in laptop) to test actual useable bandwidth.