We're locals and eat at a resort TS every couple of weeks. You'll need to provide documentation at the parking booth. Usually I have the reservation info up on my phone and hold it up for them to see; a couple of times they've asked for photo ID and compared our names to a list and once they scanned our magic band. If you go for an early breakfast, keep in mind that some of the resort shops open a little later than in the past (we once went to Whispering Canyon for a 7:30am breakfast, finished at 8:20, and found out that their shop didn't open until 9; I think they moved up their time to 8:30 but I'm not sure).