Can you refrigerate a cake that has been iced and covered with fondant.

Sure. 

If you don't want it to sweat, box it in a cardboard box.  Set it on the counter in the box and let it come to room temp over several hours before removing it--that way the condensation goes to the box, making it damp rather than the cake surface.

If you're worried about smells transferring to the cake, then you should also wrap the box in at least 2 layers of saran wrap.