PROBLEM
You can set a “custom distance” on a spotlight, but sadly, the orange cone in the viewport doesn’t reflect this.
(And I don’t get that center line at all, which also doesn’t scale. There should be an option to turn that one off.)
SOLUTION
The bottom of the orange cone should move up to whatever distance you set in the light properties.
This is a UI consistency break, since size, blend and radius does get reflected in the viewport.