I will be travelling with the wife, who can't understand why it can take longer than 15 seconds to take a photo, and why would you bother walking around to find another angle. So I am normally under time pressure which also means that constantly swapping lenses just ends up annoying the wife, which in turn end up annoying me. But I am sure a lot of you can understand that situation !!!
When my wife and I were last in Paris, I very nearly ruined everything by being too preoccupied with taking photos. Since that experience (over six years ago at this point), we have come to realize that having some separate time when she can shop and I can snap is invaluable to continuing our loving relationship. If your wife is amenable, try to have some apart time when you can take the time you need to get your photos and she can do whatever she wants to do. She will enjoy the photos; what she hates is standing there while you are fussing and she is getting bored.
Looks like you are getting a split of advice between the wide angle folks and the telephoto folks. I fall into the latter camp and would not go on vacation without at least my 70-200 f4 L IS. For that reason, I recommend that you take your 70-300 for capturing detail. I agree with the 16-35 as well. The harder one is the 24-105 vs the 50. In your case, I would opt for the 24-105 because often you won't have time to swap out to the UWA or telephoto and much of what you want will be in the 24-105 range. I would echo the 40 pancake. If you can, pick one up and have it for an ultra light option.