Thank you! After reading this post I went back and checked out photos from my 2018 British Isles cruise. I took the vast majority of them with my 6300 with the 15-135 lens. I took a few more with a wide angle. My favorite stop was Glasgow, we took a private photo tour and it was fantastic.
Tom took us all over the city and they have great street art, churches, museums, buildings, etc and he took us to all of it.
So I think you'll do great with that lens.
Vic