I didn't find a Brit-speak list that had pipped at or pipped to the post, but I did Google "pipped to the post".
Most of the entries were pipped AT the post, and did mention last-minute events. The one that had pipped TO the post was an article about foot-racing with oranges in Devon...and they say WE'RE weird.

I know that the British refer to the seeds in fruit as pips, and I read where someone called the warning tones in a pay phone pips.

It may be that the article implied that, although the get-out-there-and-get-it guys are going to continue to develop their projects, the hey-we-found-a-way-to-get-it-while-staying-home guys are going to make enough progress that the need for some of the go-away projects will cease to exist.

As to nipped at the wire: I have seldom heard that. I have heard edged out by a nose, beaten by a nose, and more commonly, nosed out at the wire. Here at Churchill Downs, and at other U.S. racetracks I have heard races called at on TV, if the announcer says "the Post", that means the starting post. That's why the horses' placements in the starting gate are called Post Positions. Is that the way it is at Pimlico, Bob?