So I noticed something while (re)watching the trailer for the new adaptation of Les Misérables: there’s a brief shot of Valjean (Hugh Jackman) in a decrepit church, and it appears to be the exact same one used for Bastogne. Whaddyaknow!
It’s a bit hard to tell from the BoB caps, but compare the window and lighting (cap 1 of the lower set), the gilded altar (cap 2; the cloth barriers on the sides seems to have been removed for Les Mis) and the blue-and-gold ceiling (cap 3; the stars are the same). Click on the pictures to enlarge them and get a better look.
(Apologies for the terrible quality of the caps, by the way, and NB - this location was also used for season 9 of the BBC’s Spooks, though I couldn’t for the life of me find a cap of it.)