If there's a mod to move the Circus somewhere else, then Quayle and Aerie will obviously go there with it. But if the Circus is simply removed, (which it very well might be: With total assets of two roulette tables, three animals, and a big tent, Quayle might as well just chuck the whole thing), then they should have someplace else to go.
Raelis Shai does make sense, but that means considering whether or not the party has done the Planar Prison, which is more complicated than this needs to be. (It works as far as Quayle sending an in-party Aerie to come see him at the Five Flagons, but I'm thinking broader-scale here.) Quayle's good with finances, so I say let him get a job helping Ribald while Aeire learns what she can from Lady Yuth.
And then there's the (admittedly remote) possibility that the party puts off doing the Circus quest until Chapter 6, meaning that the change to the Waukeen's map removes that opportunity. In that eventuality, it might be neat to have a few Commoners (e.g., the Harrolds) talk about how great it was that some other adventuring party came and saved the Circus. Continuing on this tangent, Let's say you can actually meet this other party some time down the road: Maybe you fight, maybe you don't. Maybe you convince Aerie to transfer right from their party to yours--if your alignment/conversation responses are closer to Lawful Good than the leader of the other party. I might almost suggest that the leader of the other party be a Bhaalspawn, but that's getting a little too parallel universe-y. But still Quest Pack, though.