This map suggests that the West Midlands and Manchester conurbations are much larger than the others (Sheffield, Nottingham etc are no shown, sorry):-
so the idea would be to prune the eastern branch - run new track from Birmingham to the outskirts of Derby, then on conventional track through the city (thus serving it, rather than building an expensive new station at Toton) more high speed track to the outskirts of Sheffield, similarly proceeding to the outskirts of Leeds (here I think it could be more problematic since Leeds station is notoriously full. However there have been complaints that the new Leeds terminus is a long way from the main station which would inconvenince those wanting to change on to local services.)
The rail lines in the East Midlands are not as congested as the WCML tracks, and there are splenty of disused rail lines that could be reopened if freight trains needed to be moved out of the way. Or of the 3 stretches of new track only 1 or 2 could be built.
Similarly, the ECML (lines out of Kings Cross) is not as overloaded either, so upgrading this line can be contemplated (there are plenty of stretches where there are only 2 lines, and there are notorious bottlenecks such as the flat crossing at Netwark and at Welwyn both of which could be usefully removed to great benefit. The Lincoln avoiding line can be electrified which would provide a valuable diversionary route and assist freight trains to move to this route.)
So there is scope for trimming the project. These sort of cutbacks could be implemented if the project starts to run over budget provided the phasing was chosen appropriately (eg Toton station).