The report I linked suggests it would be cheaper, by around 50%. Less track, lower speeds etc. Some of that saving would be wiped out by re-design costs, but it is worth investigating further IMO.
It will be some time (when?) before HS2 is planned to reach Handsacre. There is time (not unlimited though!) to (re)consider how best to link from there to Manchester (and Liverpool, Leeds, Warringon, Wigan, N.Wales, Scotland, etc).
Some questions to (re)address? How many (if any?) passengers using HS2 for the southerly direction might be expected to want Manchester Airport? The much larger Heathrow requires a change of trains at Old Oak. There are IIUC 6-8 tph Piccadilly-Airport 13 mins direct- 21 minutes 'all stns'. Heathrow- Paddington 20-35 mins.
Might a routing for a two-track 'slower' classic lines HS2 be found on existing (or pre-Beeching) formations, maybe with limited 'interventions'?
Could construction start from Piccadilly, or some other easily accessible location, suitable for onward travel into 'Manchester' or beyond? I'm conscious of the relative 'inaccessibility' of East Lancs to London (if indeed there is a 'market/ need' for that, and the perceived (political?) need for HS2 to reach Leeds.
I very much appreciate that redesign costs time and money- it needs to be considered as part of the mix. To my mind 'something' is better than the current offer of 'nothing'; the great is the enemy of the good.
'Along the way' I have long been 'intrigued' by the alternative routes available through Staffs where capacity is both provided and limited by tunnels, two- track portions and flat junctions. Might that be another (subsequent?) 'project'?