In the sixth film, it's revealed that Dumbledore is able to apparate within Hogwarts' grounds.
Harry Potter: But, Sir, I thought we weren't allowed to apparate on Hogwarts' grounds.
Albus Dumbledore: Well, being me... has its privileges.
Does Polyjuice potion effect apparation restrictions? If a Deatheater, or anyone else for that matter, was to disguise as Dumbledore, would they be able to appare within Hogwarts? Or, the other way round: if Dumbledore was to disguise as someone else, would he then be unable to apparate within the Hogwarts grounds?