In a ‘65 Yeti. An intermittent fault causes the screen to freeze and lose all functionality. Then it starts working again... 

The local Skoda dealer says the only way of dealing with this is a replacement unit @ £1400. Because they say, the software is no longer supported.

Any advice on how to deal with this for less money?

Thanks

I had the same problem on the Amundsen Unit in my Ex 230 Vrs, same symptoms as yours.  There was a software update which seemed to cure the problem although I had the screen replaced twice. Itss a common problem which Skoda DO know about.  On my 230  radio was only a screen and the actual unit was in the glove box, is yours the same ?

The unit I've got seems to be integral. It is mostly working at present so I'm living with it. I've also been in touch with these people who seem to be potentially helpful: https://www.satnavsystems.com/

My car developed a couple of unrelated faults / error codes at around the same time for which the main dealer wanted £1500 to sort out. My friendly neighbourhood garage has checked it out for a small fee, cleared the error codes, and thinks everything is probably OK!

I'm thinking there may have been an electrical glitch which generated the error codes and at the same time knocked over the Amundsen unit. Fingers crossed.