I traveled for 10 days in Rome and parts of Italy just over a year ago. I took over 8000 images in those 10 days (of course some being bracketed of the same image). At that time, I didn't have my 5dMark II, I only carried a Canon 50d and 20d, both of which only have a max, usable ISO of no more that 2000. I carried a 10-22mm f3.5-4.5, 24-105mm f4, 50mm f1.4, and a 70-200mm f2/8 with a 1.4x telecoverter.
Although it would have been nice for a bit more reach, that would have only affected less than 5% of my images and not worth any more extra weight. What I would seriously consider on any future trips is how to capture images in extremely low light (churches, buildings, night shots, etc).
Regardless of the equipment, I was able to get some amazing images with what I had, used Aperture, and the Nik Software suite to work on them and am very pleased with the results.
I have been to Bavaria a few times before as a company I worked for had it's mother company in Burghausen Germany. This was the pre digital days and I managed to get some amazing shots with a 50mm and a 70-300mm lens. Best part about it was I had to think about the technical aspects of the shot, take it and than see it when the film was developed when I got home.
Use what you have and work within the technology rather than being a pack mule for equipment you might / might not use much. I'm sure you have seen it, although there are some great photographer in this thread with sound advice as well...
http://www.texasphotoforum.com/forum...my-camera.html
Good luck