Many thanks for all your replies.
I take it then that, unless specifically stated by the next sector, there is no need to meet the previous restriction.
This only actually came into play the other (busy r/t) night coming into LHR from the east: Cleared FL150 by Saber after passing Logan at 250 - now have 10000 ft to lose in 25 miles: Add to this going into cloud (anti-ice on), a tailwind and wanting to slow down from a high speed descent due turbulence, and it all got a bit sporting... until reaching 150/Saber by which time we only had about 3000 ft to lose before going into the hold at LAM (30 miles away). Just left me thinking whether we did actually need to keep up the downward dash having been transferred and recleared before reaching Saber (which we did)
I should -of course- have asked, but that's what this post was for!