Well according to realtime trains, everything booked to stop there today (Sun) has done so, more or less on time.
Saturdays shows everything running towards Manchester, but not towards Sheffield, and Fri showing many cancellations.
I know that doesn't answer your exact question, but the damage can't have been that bad, or else an inspection has shown that it's not enough to affect services today.
On the other hand, National Rail Enquiries says "some" only running to Marple, and "some" diverted via Stockport until further notice.
There's a link to a Northern twitter picture of the damage:
https://twitter.com/northernrailorg/status/426716004300099584/photo/1
So maybe there's less of a problem today with less traffic running to allow them to do single line working?
Enough speculation. Anyone have any solid info?