After more than a year trying to make it work, usually with marginal results, I finally gave up the Wi-fi link to the remote station. Armed with 60m of white UTP cable, short and tall ladders and some helping hands, I changed the internet connection of the remote station to a wired link.
The results were immediate, and now I can access, control and hear the remote radio with much more reliability.
I definitely do not recommend a lengthy Wi-fi connection at the station end for remote operation use.
Another tip from the learned lessons book is that you have to use first class workmanship on all items of the station. Both good material and careful execution are essential. For a few weeks I could not access the radio, and when inspecting it on site I found a bad Powerpole connection on my RigRunner (my fault, Rigrunners and Powerpoles are great). This knocked off my Microkeyer, killing the link between the PC and the transceiver.
Now everything is online again, with decent response speed.