Welcome to the forum.
Looking on the bright side, we're just going into the low-adhesion season now so all the slipping and sliding that's due to occur will create work for the railgrinders to fix. That should get them out and about.
They're quite impressive things to see working in the dark with all the sparks they chuck out. And it's even prettier when they start small lineside fires.
I guess the only people who know the timings are the crews who operate the machines and the people who roster them. You need a spy in the Balfour Beatty or Network Rail camps methinks.