How to template a view and be able to manipulate the content with it? I'm wondering if there's a way to template a View, and actually be able to manipulate the content within it. I know I can theme the 'wrapper' around the View, but I'd like to be able to override what's inside the View, so I can create my own loops et cetera.

Right now I'm just having to create a view, and then make a template for the block (block--views-block--view-name.html.twig for example). This doesn't give me any access to the fields within the view though. I just have to wrap my markup around a {{ content }} tag, and adjust the formatting settings of that view.

I believe this functionality was available in D7, can I do it in D8?

EDIT:
Another example I just thought of is if I had a content type for locations of offices, I then made a view to display a list of these locations to show on a page. I want to be able to have access to data stores inside each location. This way I can then create loops etc on my contact page, looking through each location, displaying it how I'd like.
You should create new display modes for the content in question, and provide twig templates for them (e.g. node--type--display-mode; I am unsure of the pattern). Then you can change the View to show the rendered entity, and select that display mode, which will use the twig template for it.

This will be a lot easier IMO for what you are trying to do and make the View itself more maintainable long term. For example, maybe you wind up having to make multiple views... editing all those fields via Views is going to become a real pain real fast. Changing the field configuration in the display mode settings of the respective entity type will be reflected in the View immediately without changing the View itself (unless caching is enabled, then clear it).

See: http://www.mediacurrent.com/blog/drupal-8-theming-without-panels for some background.