I know you see a lot of theater, but this sounds really special. What's the deal with NT Live? Is it one of those closed-circuit broadcast things to different venues? I'd love to catch this. The cast sounds really solid. I'm glad Nathan Lane is taking roles like this. PBS showed The Nance as part of Live From Lincoln Center not too long ago and he gave a stunning performance.
NT Live is a process whereby plays at the National Theatre in London are transmitted to movie theaters in the UK and US, to audiences who pay to see them, like movies. The dates are publicized well in advance. The cost is a bit more than a movie, but much less than a play. I know friends in NYC are planning to see them soon.
Because the National Theatre has the infrastructure, sometimes they are hired to transmit other theaters' plays as well.
Here's the link, go to "Find a Venue," put in your country, city, then you'll see the venues available to you. Actually, some of the theaters in the U.S. seem to be showing Part I on July 20; Part II on July 27. But search around your area.