Lens choice for Trip to Italy

I'm going to be headed to Italy for the first time very soon. We'll be visiting Rome, Cinque-terre, Pompeii, Florence, and Venice. Since I am travelling with a toddler, I need to keep my kit fairly light. I am shooting with a 5d3.

Originally, I had planned to bring my 17-40 and my 24-70 on the trip, but I'm worried that I don't have anything long enough. (My wife is strongly against bringing my 70-200 2.8 IS).

A friend has since offered to lend me his 24-105 (in exchange for my 24-70) for the duration of the trip.

Do I need longer than 70mm when visiting those places in Italy? Should I take my friend up on his offer?