I call this "cutting down to the nubs". Most people would never dream of doing this, and if their gardener did it to one of their plants, they would probably have a fit. And that's why most people end up with scraggly-looking cape honeysuckle that barely flowers. Luckily, I can do this myself, and I do.
This plant has been here for over twenty years. Normally it's kept trimmed to just under the window, so I guess it's about 3-4 feet tall. Now, of course, it's just nubs.
I first learned about this when I was going to ASU. No, I didn't study horticulture (I was an art major) but I was one of the people who noticed when the beautiful hedges around the art building were merciless cut back to nubs. Typical of people who knew nothing, we were outraged, and there was some talk of maybe going to someone to protest this outrage. But of course we had no idea who to protest to either. And then the hedges came back, full and beautiful. I still remember seeing that, and a light bulb went on. So that's how you do it! Hey, you can learn a lot in college!
Yep, that's how you do it. Get a trash bag, get your cutters, settle in for a few minutes, do it in the shade if it's summertime (and you really shouldn't do this when it's cold), and cut it back to the nubs. It will be the saddest-looking little plant you've ever seen, and you need to not look at it for a few days. But cape honeysuckle comes back strong, and grows fast, so it will be needing another trim in just a couple of weeks or so. But that will just be a light trim. Cutting to the nubs you can do every few years, or when the mood strikes you.
Be prepared for people to scream at you, "what are you doing?", and you will need to practice your best knowing smile. And then watch your Cape Honeysuckle come back more beautiful than ever. People will go from thinking you're an idiot to a genius almost right away!