Busses will be fine, but not going to lie... if this were me and my only choice of Disney transport for EMM is a bus... I would probably opt for an Uber/Lyft/Taxi/Minnie Van, if any are an option for you. It can sometimes be worth it for the peace of mind / better control over your exact schedule that morning, for us at least. If you do take Uber/Lyft/Taxi/Minnie Van, get them to take you to CR and have the driver drop you off just past the security gate. (ETA: Correction on the Minnie Van part, they’ll take you directly to the MK bus stop area).