What is the interval between these screenings? I suppose it all depends on what episodes they decide to show, but I know I'll definitely go if they show "All Good Things..." That still remains one of my favorite episodes of any Trek show ever.
For the first three seasons, they have always shown the episodes in theaters the Thursday on the week before the release of a new TNG season on Blu-Ray. I'm expecting it to be the same for season four. You just have to keep an eye out for it by looking at theater listings in your area for that night you expect it to be shown. It's a Fanthom Event so each of these showings have been one night only.