I've never found that to be the case with overcrowded dance floors...but then again, I'll dance anywhere, in the aisles works for me.
:boogie:
I think you'll be fine with finding plenty of room and places to dance. As I sit at the champagne bar which overlooks Rendezous, I've never seen it "overly crowded". I think it also depends on how long your cruise is, what your destination is, etc. Some cruises are predisposed to retiring for the night early, others not so much.