Crowne Plaza rooms in the main wing are big enough for fit 2A + 2C, if you don't mind the younger one sharing your king bed, and the older one in an extra bed. The rooms in the main wing are very well maintained despite being older (hotel opened in 2008), but are much bigger than the rooms in the newer Jewel Wing.

Crowne Plaza is not near the airport. It is IN the airport, at Terminal 3, which is accessible via the skytrain. If you luggages are interlined through to your CX flight, you can even walk from T1 to T3 and clear your immigration procedures at T3 instead and walk directly to the Crowne Plaza.