The original production of Pippin, and many of the ones after, have framed their production as a traveling circus.
Reefer Madness (both the musical and the movie musical) are a dramatization within a propaganda lecture.
The Rocky Horror Show is especially meta- the opening and closing number frame the story (either movie or play) as being a fictional B-movie, but the story itself is a reenactment of an academic's case study (a throwback to sci-fi legend H.P. Lovecraft).
Cabaret is obvious well the old one. The doesn't use the travel element but has some ideas. The Scottsboro Boys. I could stretch it and say Curtains to some extent.
I wanna say Prince's Candide. The opera house presentation and the 97 revival, perhaps the 73 revival too, I know it had a circus like pageant wagon atmosphere.
SHOWBOAT MAN OF LA MANCHA (as a sort of captive improv troupe) ZORBA (bouzouki taverna troupe) HAIR (ragtag hippy tribe) GODSPELL(ragtag hippy tribe) GRIND (vaudeville burlesque company) THE WILL ROGERS FOLLIES ASSASSINS (carnival midway) STEEL PIER SIDE SHOW THE GLORIOUS ONES (renaissance acting troupe) and apparently CHAPLIN (have only seen preview video)
Sure, most of these aren't TRAVELING troupes, but vaudeville/circus troupes just the same.