No one sensible is talking about a high speed north route of Golbourne/Leeds because it isn’t going to happen. Post phase 2 will be all about incremental upgrades to the existing lines with maybe short by-pass sections, achieving the best value for money.
HS2 proposed a route that got within a relative handful of kilometres of York after all.
Golborne has an outside chance of happening as part of NPR, but its not particularly attractive otherwise given how much extra track it needs.
Leeds will probably need serving, and from our present position the most likely route is probably Handsacre-Manchester-Leeds. With Meadowhall gone the Eastern Leg doesn't seem likely to be attractive, Chesterfield-LEeds is a long way just for Leeds traffic. Plus that means any money spent on NPR gets used for this too, and vice versa.
And once you've done all that, continuing to near York is probably the easiest way to get to Scotland quicker.
But this is rather peripheral to the topic at hand!