If really cannot then no choice but go wifi repeaters. My uncle's house uses 4 Mikrotiks, one is the main router/AP and 3 more as WDS repeaters. Works quite well. In addition to that, 2 more Mikrotiks as a WiFi bridge just for the HyppTV. Walking into his house is like walking into a microwave oven. :-)

How about Homeplug? Maybe can try that. I'm using Aztech 500mbps Homeplugs from my router located upstairs to my HyppTV downstairs. Very stable. HyppTV only require max 10mbps to perform nicely. When I installed them I did a quick file transfer test and got about 350mbps sustained through the homeplugs. My house is old and is single-phase electricity so it's OK. 3-phase supply may pose problems if the power sockets are on different phases.

As for the Mini, just look in the trade zone, should be a few there.