You don't need new cables ..you need a buffer.
My God, I actually have one of these! Haven't used it in years. I'll give it a try.
You may be right, but I did notice that even over this length there were differences. When I compared cables for this purpose I was looking primarily for no observable impact to the video. I tried the Silver Serpents and the Blue Jeans offerings. I chose the SS because IMO it offered slightly better video transmission, but I do remember that the Blue Jeans cables did sound a bit better for the audio side. The difference wasn't so great that I was bowled over, so I chose the SS bundle.
Easy enough to try the buffer, though. All I have to do now is FIND it!