5 years of disruption sounds entirely plausible given that the Manchester - Leeds route mileage (based on my crude dot to dot Google Maps calculation) is almost exactly the same as Manchester - Blackpool (minus WCML). There's been weekend closures for years, and early am services have been RRB.
Something to consider is the availability of resources for electrification, given there's going to be HS2 construction, MML still to complete, and any other surprises Grayling might announce
Manchester-Preston (25 miles) will have taken 4 years to upgrade by December (boots on ground etc), longer if you count the Euxton Jn redoubling.
Much of that was general route improvement (Chorley Arches, Farnworth Tunnel, Bolton P5 etc) rather than electrification per se.
There have been repeated long blockades over parts of the route, as well as practically continuous overnight/weekend possessions and disruption.
NR managed to do Preston-Blackpool in that time too, also the Ordsall Chord, though they were disconnected projects.
Manchester-Leeds is 40 miles between the wired bits, with many obstacles and generally ancient infrastructure, particularly on the west side.
Any route realignment or tunnel reconstruction will be very disruptive, even with the Calder Valley as a diversion route.
I can quite see Rob McIntosh's point.
Still, it's useful to see a list of the work envisaged, and a timescale within CP6.
Digital signalling seems to be the magic ingredient for Huddersfield-Stalybridge, instead of wiring.
The TfN press release also confirms a budget of £3 billion.