I don't use LR but I used a smart album-ish sort of approach to back out how little I use the 70-200. Since I got it in 2012, I have captured:
- 1,759 pictures (from any lens) that I personally peg as a 3/5 star or better shot.
- Only 105 of those were taken on the 70-200
It's a stellar, stellar lens. But I use it 4-5 times a year for the odd portraiture need or occasional varmint spotting while hiking or camping. It will not join me on this trip due to weight, what I prefer to shoot, and the relatively close confines of the city.
I guess you and I shoot quite differently. I've had a career as a photojournalist, sports and on-location commercial photographer. Many situations would come up where, despite packing a long tele, I could never get close enough. Even if I'd carry only three lenses, one would be a 300 - or longer.
I agree with you, in the city, a good wide angle is likely to be the lens most used. That's why the 16-35 is an obvious choice. But, unlike you, I find the 50mm focal length unnecessary and it's perspective uninteresting, which is why I'd want something longer. I'm just not sure that 70mm or even 85mm is enough for a lot of cases, say on the ferries around Copenhagen and Stockholm or when you want to zoom in on a architectural detail or isolate your subject.
You're right in that the 70-200/2.8 can be burdensome when you're trying to travel light. (I'm afraid I'm so used to it. In fact, it's the shortest in my three-lens kit when I shoot sailboat racing (the others are 300 and 500, and, yes, hand held). You can save a little bit of weight by removing the tripod mount. Or, better yet, rent or borrow the f:4 model; the IS version won't disappoint you.
I went back and looked into my catalogs to see what lenses I used most on recent overseas trips - Danube, Middle East, Greece and Australia. By a large margin, the 70-200 was my go to lens, with the 16-35 being used less than half as much. Even if I looked at only what I photographed in the cities, it still made up nearly half of my shots.
While I don't know how you shoot or what are your particular subjects (you can probably tell I don't have children), but I would think having something long (at least 100mm anyway) would be a good call. It's probably my photojournalist training, but what I most want to bring back from my trip is the story of where I've been