Interesting.......can you elaborate?
Could I run a 30m ethernet cable to the Shepherds Hut/mancave then put another router on the end creating a separate local network for that area?
If running a cable is possible and you have a spare port on your Alncom router, that will deliver the best results, its what i would do (and have done!) however you dont really want/need a router on the end of it (leave the one in the house to do all the 'routing'), you just need an access point.
Just to expand on that to clarify in layman's terms - an access point merely broadcasts the internet that is fed to it via a wired connection, a router does a little more, typically assigning IP addresses, perhaps acting as a modem to connect to your incoming internet. Having 2 routers on one network will result in 2 separate network islands which can cause issues if you wanted to share things between them. that said, routers sometimes have the option to act as AP only, so if your reusing old hardware check that out...if not access points are pretty cheap.
Final point, if your running an ethernet cable outside, make sure its in a conduit, the regular stuff is not UV stable, so will degrade over time. you can buy outdoor rated ethernet cable as an alternative, but obviously you have to be careful not to damage it whilst gardening etc..
Just to go against all of that though, as if you only achieving 20mbps from your internet connection and assuming your property is on a single phase supply (or at least are confident both the remote and home locations are on the same phase), you could give a powerline adaptor a go (obv make sure you get the one with a Wi-Fi transmitter at the end, some of the cheaper ones just give your an ethernet port) as they will be able to handle that sort of speed without issue. as has been mentioned however if your mains wiring is a bit of a rats nest, they may or may not work reliably, so buy from somewhere with the option of sending/taking it back if they dont meet your expectations.
