Most guests are offsite but disney has been closing the gap steadily by opening more hotels there are lots of estimates but only disney knows and they arent sharing. Disney keeps their hotel occupancy pretty high above 85% and has about 36,000 hotel rooms onsite so you gotta think those hold 90-120,000 ppl at a time. You can get the TEA attendancebnumbers and then divide by 365 for all 4 parks and 2 water parks to get a very rough average of the daily attendance.