Whittaker

Hi all, first post but I've been lurking for a while. My question to the touring community is this.

I currently have a Dawes Horizon (possibly early 2000s) touring bike, replete with rack and back pannier bags. I have ridden this across half of Europe and many other places, and it's been good to me.
However, I want to ride across all of Europe and further out East possibly next year, and I am thinking of ways to make this a nicer ride in terms of the setup.

I recently did an ironman and borrowed a Feltz F4 for it. It was unreal how light it was, possibly largely due to the carbon frame. I also rode (unsupported) the length of the UK with an old racing bike (80s) racked up with back panniers. I know both of these bikes are meant for unloaded speed hops, but since the old racer made the UK ride and that was pretty light I'm curious about how to make this ride across Europe faster and lighter than the fully loaded Dawes.

I know some of these round-the-world speed attempts go for fast expensive light rides, and those sponsored custom jobs are certainly out of my price bracket - but any thoughts on a happy medium?

Perhaps people have experience of taking the bare minimum kit too? Possibly getting by with just one of those saddle duffel bags too?