Bring a 100-400f/4.5-5.6L IS II or a 70-200f/4L IS to Paris?

Pietro Marchesi wrote:

Is it worth it to bring a 100-400f/4.5-5.6L IS II instead of a 70-200f/4L IS for a 9 day family vacation to Paris, Versailles and Disneyland Paris?

Obviously the 100-400f/4.5-5.6L IS II is larger and twice the weight of my 70-200f/4L IS. What will I gain having easy access to twice the focal length in Paris?

I use a 6D and will also bring my 24-70f/2.8L II and 16-35f/4L IS. My wife will use her small Sony RX100III and and our son his Panasonic LX7. We all enjoy taking a lot of photos.

I always bring 6D + 24-70f/2.8L II as my main lens everywhere I go, always ready to shoot never in a bag. i find 24-70f/2.8L I is perfect for most family/people shots and I almost always also bring my 16-35f/4L IS and 70-200f/4L IS in a small rucksack for when I need a wider or a longer lens.

On our latest trips to Istanbul, Rome and New York my most used lens was my 24-70f/2.8L II but the 16-35f/4L IS has been invaluable, especially useful indoors in museums and large churches.

On these trips my second most used lens was as always my beloved 70-200f/4L IS but I sometimes wished I had more reach than 200mm, especially in Istanbul and even more so from the cruise ship. Will I miss not having more reach than 200mm in Paris?

Has anyone here used a 100-400f/4.5-5.6L IS I or II in Paris?

i traveled and worked  overseas for 5 years and had my 17-40 f4.0/70-200 f/40 IS on a aps-c camera! this setup worked beautifully for me! for city visit, your 24-70 f2.8 II would be used the most, in my experience!

since you are using a 6D FF camera you may spend most of your time in the city, i think your 24-70 will be enough but i'd take my 70-200 as well. but 100-400 L will be too much in weight and reach (more than enough), so i'd leave that behind. YMMD.