Hi Corine! How were the holidays?
Devices are only an indication. Designing for a given breakpoint most likely addresses each device with a given orientation.
But in fact the responsivity works with pixel dimensions of a viewport. Regardless of the OS, the model or the type of the client device.
So you have to take that into account.
Corine I wouldn't be so concerned about landscape phone: it's a very tiny portion of user that will view your site this way
The most delicate is that a landscape tablet will show the desktop breakpoint. So when using videos, or bg videos, it can be a big issue. For some sites I had to resort to a script that detects the OS of the client browser and serve different kind of content.
Now, knowing all this, can you sort things you can deal/live with and things you'd like to be addressed, and tell me?