We've had good luck getting a FP for the princess meets at MK after using our first 3 FP. The standby line is also short right at rope drop and close to park close, either of which could be a good plan depending on what else you have planned. If Rapunzel is a big priority you could also look into the Bon Voyage breakfast at BoardWalk (Trattoria al Forno Restaurant). The characters are Rapunzel, Flynn Rider, Ariel and Prince Eric.