Hello Matt,
Thank you for stopping by the Disney Parks Moms Panel with your great question.
Disney's Magical Express and
Resort Airline Check-in are both wonderful hassle-free services that my family always takes advantage of. So, I am glad to hear that you are already thinking ahead in regards to this awesome benefit for guests staying at a Walt Disney World Resort hotel.
You are in luck! You can absolutely check your bags and get your boarding passes in the morning for an evening flight. We have done this on several occasions as we like to spend the day in the parks before our departure later in the day or evening. The resort airline check-in desk is only open for limited hours in the morning, from 5:00am-12:00 noon. The only timing restriction is that guests wishing to utilize the service must check-in no later than 3 hours prior to their departure time, but there is no limit on how early you check your bags. There are a few airlines that do NOT participate, so be mindful of this and check the link I provided to see that your airline carrier is one of the participating ones.
If you do intend to spend the day away from the resort, either at a resort or maybe Disney Springs, the bell stand can hold any carry-ons you are not checking and do not want to lug around with you all day.
Have a magical visit and feel free to stop by with more questions.
~Allison L