How was any government going to re-open pits that had been derelict, flooded, ruined, and the infrastructure demolished? Where would the skilled labour come from?

Her destruction of the TU movement was so deep that no government would have been able to revive it - the Self-Servatives and their big-business/financial cronies would never countenance it, and would stop at nothing to prevent it.

No, the damage wrought on the UK by the Beast of Grantham was so complete that much of it was, and is, irreparable.