There is nothing in the non-exhaustive list of reasonable excuses (for not staying at home) that makes any provision for people to leave their homes (let alone drive 250 miles) to find the best childcare arrangements. What is more, at least one person in the car was certainly infected meaning that The Coronavirus Act comes into play which imposes further restrictions.
This was not a life or death issue for their child. It’s preposterous to claim that childcare could not have been secured in London for a man of Cummings’ means and stature, especially with an in-law and assistant close by.
Sure it wouldn’t have been ideal, but it’s not ideal that people have missed saying goodbye to dying family either.
What certainly happened is that Cummings didn’t fancy spending the next two weeks being shut up in his London house; a person such as himself has every right to run off to the more pleasant surroundings of his parents’ property in Durham. He’s special.