Canon travel kit advice - camera and lens combo for Europe

I will be headed to Switzerland for vacation in August, and am thinking about what camera gear to bring. The purpose of the trip is not photography but I have never been to Europe before and am excited about taking pictures of our vacation. 

My current bodies are a 5D Mark II and a 1D Mark IV, and I am wondering if I should buy or rent a new body prior to the trip. Even though the 5D2 has been my go to travel camera due to its size, I really dislike using it for anything other than landscapes and nearly static subjects (the autofocus is absolute crap), and the 1D4 is too big and bulky to travel casually with. I have been waiting for Canon's sensor technology to catch up to the high ISO performance of Nikon and Sony's sensors before upgrading, but that doesn't fit with my trip timeline.

Is there a newer Canon body without an integrated vertical grip that performs much better than either of these models in low light and has accurate, fast autofocus focus tracking across well spaced AF points, even in low light, and shoots a minimum 5 fps? I'd prefer a full frame sensor as I absolutely hated the 7D, and want to prioritize ISO performance and shadow details, which are generally handled better on larger sensors. I love my 5D2 for landscapes, I just need something more capable of shooting on the fly, with a similar form factor. How do the 6D, 6D2, 5D3, and 5D4 compare? Is something nearing release that I should wait for?

Similarly, what would be your go to Canon-mount travel lens if you were only traveling with 1-2 lenses? I find that I have been using my 50mm f/1.4 and 100mm f/2 primes a lot lately for the speed, but I think a zoom would be helpful for travel and I only have zooms that cover the 17-40mm and 70-200mm ranges (both f/4). I've traveled plenty with my current kit before, so I know I'm full capable of creating great images using it, I'm just wondering if there is a way to simplify my kit while maximizing my shooting options, especially considering I haven't upgraded cameras or lenses in nearly half a decade.

The 5D2 and 1D4 are absolutely ancient and are mid 2000 decade technology so a newer model will give you much better results for image quality, dynamic range, detail rendering, noise, AF, et...  A 5D4 will far outperform either of these on every conceivable level.  Perhaps a single lens to keep the kit simple like a Sigma 24-105 which is slightly better than the Canon 24-105 II.

Maybe rent the 5D4 if you're not ready to upgrade.

I do not know much about the Canon camera line, but I do have some recommendations for lenses for a river cruise based on my Danube River cruise last year. For shots of those wonderful castles, etc from the boat, you will need something like a 70-200mm to bring some of them closer to you. And make sure you have something wide enough for city scenes from the river and in the cities, like a 20mm or even wider. And an all purpose zoom lens for everything else. On my trip, I was the only one with a traditional DSLR. Others were using point and shoots, cell phones, and a few had a mirrorless camera. .

Switzerland to me means a lot of hiking, landscape and citiscapes. If you are willing to carry the weight, the 17-40 and the 70-200 will do the job with the 5DII as i do not think AF is important. If you don't want to upgrade, i would put my money towards a suitable camera bag. However, i jumped ship not a long time ago, exactly for reasons of ancient sensor tech. and wanting a lower weight kit. 

Thanks for all the great suggestions. I'm certainly not considering switching systems - I have a lot invested in Canon and managed to snag a lot of fantastic deals on good glass that I am not sure I could replicate if I switched. I still take much better photos that people I know who have much newer cameras.

I'll probably keep my eye out for a good deal on a 5D4 kit (perhaps a used 5D3 for a bargain) and when the time gets closer and we have a better idea of our itinerary and see if that's something I want to invest in. I've done fine shooting with the kit I have on other trips, it's always just tempting to upgrade when there is some special event coming up. Considering how expensive Switzerland is, it might be wiser just to spend on the actual vacation and not worry about new gear.

I also went through my Lightroom catalog from other international trips and it seems like more than half of my shots have been with the 17-40mm and 18% were with the 70-200mm f/4, so I think packing those and the 5D2 would probably be sufficient even if not perfect for every situation. Plus the advantage of using that kit is that I'll be less worried about traveling with it and possibly losing or damaging something than I would be with brand new gear.

Budget permitting I recommend getting a Sony a7III with a Metabones V (5) adapter for your Canon lenses. Then add an ultra wide prime to your lens bag for those unbelievably beautiful buildings you will find in unbelievably tight places.

I brought Olympus M4/3 gear to Switzerland and was happy with both the quality of output and the weight. I suggest you think about a 16-35, 24-105 and a 70-200 in the f/4 glass. It is light and more than adequate for quality. If you can swing it and don't want to switch systems, I agree with the 5D4 recommendation.
mike