Have a look in real time trains for your answer
I've taken that with a massive pinch of salt since there was a second Avanti from Manchester to London showing as soon as twelve days before Monday just gone, when in reality it's not scheduled to restart before the 12th of April.
Manchester does gain a second Avanti for Easter weekend only however it's a Warrington divert.
The Stoke trains still seem to have the pathetic 1tp3h timetable on Sundays.
On the topic of the Stoke trains, for how long have they been stopping at Heaton Chapel in the down direction only?
I live near Heaton Chapel - was my commuter station for years. The below applies Monday to Saturday since May 2018:
In short, HTC gains the Stoke towards Manchester, and Levenshulme gains the fast Buxton a few minutes behind it (likely the actual next train behind it; there's barely 5 minutes between them from Stockport.)
Towards the south, Levenshulme and Heaton Chapel gain the Southport to Alderley Edge to make 4 trains an hour in each direction, because the second Buxton calls at both stations both ways. The consistent stoppers, as I call them, are the Blackpool North to Hazel Grove, Manchester to Crewe, and the second Buxton when it runs outside of the (currently non-existent but railways have it in their minds that it still exists at the moment) peaks.
That means that currently, northbound can see up to the scheduled 4 trains an hour since the second Buxton runs only in the peaks, but southbound never does better than 3 trains an hour until at least the 12th, if not May, because the Southport to Alderley Edge isn't currently running past Manchester.