Setting up a Chromecast query

diyAudio Member
Joined 2007
We need to set up again as the device isn't working well.
It has been pointed up that plugging the Chromecast device directly into the HT amplifier isn't the best idea due to the large number of audio, power and HT cables behind the cabinet and all of the very solid speaker boxes between the device and the Wi-Fi extender.
I just went out and bought a new 5M long HDMI cable and a double female joiner so I could move the dongle somewhere better.
So two questions; is the shortest the distance between the dongle and the extender really important if that distance is less than 4 metres and does the plane of the device matter?
I can figure out a way to fix it to a wall in a vertical orientation or just leave if horizontal on to of the CD and vinyl cupboard, close to the ceiling and with a clear LOS to the extender. So does orientation matter?
 
It is 6500mm from the extender to the dongle to the extender and that is about as close as I can make it unless I run a cable from the router to the extender and I simply can't get under the floor and even the roof space would be physically difficult.
 
That post above should read "From the extender to the dongle [ Chromecast] and 6500mm to the router" but for some reason I can't amend the original post.
Leadbelly how have you made the physical connections and if Wi-Fi how are you doing that?