I think that it will most likely go to the Imperial. Cameron Mackintosh has been so cheapskate with his productions of late, it makes sense for Les Mis to go back on tour using the current Broadway set (regional rights were just pulled for Les Mis if I'm not mistaken).
Who knows whether the Broadway theatre will open up in time for it though. Fiddler on The Roof, as far as I know, is a purely commercial production as it doesn't have the backing of the Lincoln Centre Theatre subscriber base.
The thing is, besides being an utter toad of a human being, Riedel usually has the least knowledge of the topic in the room. He doesn't usually understand the content or approach of a show, and is always completely and unfailingly socially ignorant, which makes it really infuriating when Susan can't get a word in edgewise. A definitive mansplainer; it's always painful when he has female guests. I watch the show sporadically when I really want to see a guest, because it's the only theatre talkshow we have, but it would be so much better without this hateful clown in a dadcoat. (thanks ScaryWarhol)