We bought this cable cover for a door threshold, but never used it and so we are Marie Kondo-ing it into the world. This can hold 3 separate wires and will stretch across a 4' doorway. It is made of rubber, so if your door opening is shorter, you can easily cut this.
As you can see from the pictures it is still in the curve shape that it was shipped in, so you'll need to put some weight on it when you first set it up so that it will flatten out.