But the principles discussed are just as applicable to more normal speed 'extended range' flying.
because almost all pilots normally operate at WAY above Vbr, if you are trying to stretch your range you should
1 - In a tailwind slowdown (potentially by the whole tailwind component) as you will still arrive in a reasonable time, but with a much lower fuel burn.
2 - In a headwind you should NOT speed up, because you are already operating way faster than Vbg still air, and unless you have a tremendous headwind, you are also going faster than Vbr adjusted for the headwind component. With a piston aircraft facing a significant headwind, you are almost always better off giving up the TAS of altitude for a lower headwind (which normally this means decend) if you want to maximise range.
At a constant power setting your range is pretty much independant of the altitude at which you are operating (assuming no wind)