views slideshow: display multiple items but scroll only one item at the time
I'd suggest using the owl carousel module from Git hub for responsive slide shows.  It has lots of options to define how many slides based on breakpoints, support for mobile touch events, number of slides per next, and more.

We've been using it since 8.0 without a problem.  Note that despite the Readme, the author has released it under GLPv2.  See issue #4.

There is a cleaned up pull of this project as well.  I have not used this but it may be a slightly better alternative.

Just install the module as a manual module or you can add the git hub repo as a repository in your composer.json and install it via composer.  Once enabled, change your view format to Owl Carousel and then use the settings to define things.