Let me help a bit. With almost 2 months you can make a solid trip!
Indeed, it's too early for most timetables. Right now you might be getting strange results. Slight changes are also possible in the meantime, for example in the case of engineering works.
French timetables will be published around March-April. Check the current ones to get an idea -> major changes are unlikely throughout the year.
Don't worry about connections, they are very very common across Europe. 3-5 min is the norm in Switzerland and the Netherlands, the network is optimized like that. In most other countries I prefer 10 min.
Delays on long-distance trains in Germany are fairly common, however trains are very frequent so it's not an issue. Simply plan some margin: between Cologne and Strasbourg you'd change in Karlsruhe, allow 30 min to play it safe.
Between Strasbourg and Bayeux you'll have to transfer across Paris. Luckily it's one of the easiest Paris transfers: one stop by RER E suburban train. The Eurail Pass is not valid: get a transportation card useful for the transfer and the Paris stay after Normandy. Probably helpful advice available online!
To optimize direct trains I might suggest changing the itinerary slightly:
- Amsterdam - Cologne: 3h30 comfy new ICE high-speed train but you never run at high-speed lol
- Cologne - Berlin: 4h45-5h direct ICE, hourly
- Berlin - Strasbourg: extremely convenient new direct train. It leaves at around midday, arrival 6pm
- Strasbourg - Bayeux: 320 km/h TGV high-speed train to Paris followed by the transfer I mentioned above
I think it's a good idea to select a few bases and then plan a few day trips. Easier with luggage!
From Cologne I recommend going up the Rhine to Koblenz or why not further to Mainz. From Berlin Potsdam or even the Baltic Sea! From Strasbourg Colmar and Basel in Switzerland travelling on comfy old Corail carriages, etc.
Don't hesitate to ask anything!
I typed wrong date in original post. Trip starts 9-Aug-25 not July.
Alright, my advice still applies. You can make the most of the 25 days (24 nights if I counted correctly).
- Cologne 3-4 nights
- Berlin 5 nights
- Strasbourg 5 nights
- Bayeux/Normandy 4-5 nights
- Paris 5 nights