I did a tour similar to the one you mention, except that I started south nearer Calais. I went through France, Belgium, Germany to Munich, and then over the Alps by way of the Brenner pass, and down into Venice.
After that I trained to Lancashire, England from Venice. Then I (we) cycled to the English lake district, and over to Stranraer, Scotland. We got the ferry to Larne in northern Ireland. Then we cycled the coast and Antrim and around to Londonderry, northern Ireland. After several days in Derry we trained back to the ferry, took ship back to Stanraer, and cycled back to Preston, Lancashire. From there it was the train on to London, and a flight back to Florida in the United States.
Traffic was particularly heavy in Belgium. All in all it was a good trip. I crossed the Alps on a Schwinn Le Tour bike with only two chain rings on the front. In those days I was not aware they made triple chain sets. I wish I could remember more details about it, but that was one trip on which my notes were sparse.
I do have a detailed bicycle touring journal of over 108,000 words, most of which happened in Europe. One night in Czech I got pinned down by artillery fire, hand grenades, automatic weapons, and exploding mines. Strange but true. This was in 1994 when the wars of ethnic extermination were being carried out in the former Yugoslavia, very near to where I was cycling. That particular bike trip was the singular example of a very bad set of experiences, but realities at that time, not long after the fall of communism, were just all wrong. However, it is the tour on which I have the most exhaustive description of day to day life on the road by bicycle. I am a writer, not a professional writer, but a writer.