FYI we arrived for out Halloween trip a day before the rest of the family and we were all using ME. We had a copy of the confirmation but our other family (we found out last minute) did not. Speaking with a CM on the phone, I learned they can always scan your magic band or even confirm your name from your drivers license with the name on the reservation - she confirmed they nearly always have a "work around" as long as you have a valid reservation. Hope this may ease someone's mind in the future...