I'm probably wrong, but a time that long makes it sound like there's a compulsory purchase order or something required, perhaps knocking down an important building, which won't be allowed before a certain time? I'd imagine the Curzon St Unite halls of residence for example won't be allowed to be knocked down so soon after being built.
Why not, the're only halls of residence...
What does need reserving in land terms is the space for stations in Manchester and Leeds, considering the speed of developments in these places this needs doing sooner rather than later.
(I don't know if the Leeds Central Station site has been taken or not yet, if not, reserve please)
Otherwise all I can see for Leeds is a double decker station with more conventional platforms where the car park is on a lower deck (this is much lower than the rest of the station anyway) with HS2 on an upper deck, yes there is space) covering over to Pt.4 (Current), full re-numbering, grade separated links into roads C and D for through services, Classic Compatible only, using roughly the Wakefeild Line corridor to approach.
Massive re-numbering of Leeds City's platforms, 1 - 6 for HS2 only platforms (that would also have space to reverse out for classic compatible services onwards to Bradford, Skipton etc. 1 track link line would do) 7 to 10 for additional domestic platforms 11 to 27 for current platforms...
You think thats bad, wait till you hear what I'd have in store for Piccadilly...
1 - 3 New Platforms, Domestic Manchester Piccadilly East
4 - 15 Current 1 - 12, Domestic, Terminating Services from East, Fast and Slow (Not many from Slow)
16, 17 Southbound through platforms from Oxford Road, current 13, 14
18, 19 Island platform for terminating services from Oxford Road, build over Fairfield Street, single track link to 17 & 20 if space.
20, 21 Westbound through platforms to Stockport / Airport from Oxford Road
22, 23, 24 In former Mayfeild, platforms for slow services on the Airport Line (now dedicated tracks) and any LDPE services diverted this way.
24 - 33 High Speed Two Platforms, Four for LDPE Services to London, Two International platforms for Heathrow & Chunnel services, For 'Javelin' commuter service platforms. (In the Baring Street Industrial Area).
22 - 24 could be dropped depending on service patterns, perhaps provide two or three 'hybrid' platforms with access to the Airport lines and HS2 lines local to the station, similar to the case at Euston.
Approaches would be segregated to be:
East - Stockport Fast - Stockport Slow - Airport - HS2
If the loop onto Philips Park is put back, two more tracks for that, the viaduct into Piccadilly would technically be 12 tracks wide in some places.
Longsight would house a connection between HS2, Stockport Fasts and Airport Line. Built with stage one, allong with Manchester's HS2 Piccadilly Extension to house the new services using 400m long Classic Compatable Stock, via the Styal Branch or Stockport. The aim being grade seperation of Fast, Slow and Airport lines, with HS2 being able to access either route at Longsight provisionally prior to the tunneled approach, to Longsight.