Yes your ToD becomes irrelevant, when ATC takes you down 200 nm prior to you destination, gives you 10 step descends and controls your rate in between (all due to airspaces structures).
So what?!? Do what ATC directs. After all that, VNAV will still continuously calculate the most efficient profile from your present position and altitude. That profile will most likely be a level segment at your current altitude until you intercept the CDA profile.
If you need to start a decent "NOW", use the minimum directed/legal descent rate until you intercept the VNAV profile (which will likely be very close to the traditional 300 ft/NM guideline, should you lose the VNAV profile indicator).
Slowing down on that profile is simple: Use speedbrakes, flaps, and landing gear as necessary to add drag and maintain the profile at the lower speed. Once you're below 10,000' (where the noise nazis reside), you'll be at 250 KIAS max (generally 240 or less), so adding drag should not be a problem.
I definitely cannot understand why you consider all this information "irrelevant"! If you can plan a descent from 100 mi out, why can't you plan one from 10 or 20 miles?!?