From what i can gather the cold spell didn't just cause the edging slabs to lift, but fall off completely, as at Duffield.
The usable parts of the platform may now be shorter than a 2car unit and so, in the absence of SDO, the Conductor may only let folks on and off via the local door.
I've not stopped at Chinley for a few months, but at Duffield last week you could only just squeeze a 158 on, and that was by putting the cab section on the ramp. Tricky to get spot on when the platform is opposite to the Drivers side.