You will have little or no wait. The Disney representative will meet you as you walk toward the baggage area (look for the medium blue "sailor" jackets, you can't miss them), and as soon as they have a full bus, it will leave for the port. Our wait was maybe 10 minutes. Since you're arriving at a busy time, it shouldn't be long at all. They have your flight information (even if you booked separately, they ask for it when you buy the transfers), so they know how to schedule the busses.