If "I" were in your situation I would:
-be at MGM when it opens (I'm normally there anyway before it opens)...do as much as I could as far as attractions.
-grab my PS at either the Sci-Fi or 50's Prime (if I had kids) or Mama Melrose's or Hollywood & Vine (if no children) around saaaaaay 3:30ish or 3:45 <---keep your eyes on your watch.
-after the meal then I'd skip on down to Downtown Disney and wait around until 5:15 until Cirque starts.
-after Cirque (if I'm a little hungry) I'd grab a small bite somewhere in Downtown Disney.
*I would never do a park and a show in the same day, but then again I'm in Orlando for about 8 days when we go.