@tooner 

To be honest, the speed could be halved by losses or obstructive interference in large extent as the network is extended over long distances.

Unless you can use total wired connection to achieve the purpose of extending network rather than wireless.

  @tooner 

Ugh, more ChatGPT babble above...

You can do pt-pt with anothe outdoor 225.  You'll be limited to the max modulation rate of 867Mbps by these devices, with real world throughput likely close to the 400-500Mbps range.  You can improve the link performance by preventing any user SSID appearing on the 5.8Ghz radios (disable all SSIDs on 5.8G for the outdoor meshed pair), and by ensuring you choose a channel with the highest permissible EIRP (output power) in your region.  IIRC in the UK you are rather constrained by DFS (radar avoidance), but you might find a suitable channel that isn't too noisy.  For instance channels 149-165 are limited to 200mW, but you may find that preferable to 1000mW but with DFS if the antennas have a good line of sight, and the local radio interference is low.  You can google WLAN Channel List Wikipedia for more detail.

If you need more capacity, you could consider a pair of 6-series outdoor APs (EAP610 outdoor is the successor to the 225's) which seems to be available, though at a price! from Amazon.co.uk.  That will improve your link capacity and your effective 'goodput'.

As you are likely aware, you can use the remote AP's ethernet port like a bridge, and all device connected directly or via a switch, will appear as though connected to the same switchport that the wired AP is.