Hey there Vicky!
You must be so excited about your upcoming trip. Has it occurred to you yet today that you will be at Walt Disney World
next week? Woo-hoo!
Since the Magic Kingdom opens at 9 am on January 10th, the buses running between Disney's Port Orleans Resort - Riverside and the Magic Kingdom officially start picking up guests forty-five minutes to one hour before park opening. That 8 am pick-up time would not give you enough time to get to your reservation.
However, the good news is that a complimentary early breakfast bus starts running at 6:15 am from your resort to the Magic Kingdom. I called Disney's Port Orleans Resort - Riverside this morning to confirm that for you. I would board one of those early buses no later than 7 am to make your reservation on time. While the Disney bus will drop you off at a convenient location just outside the Magic Kingdom, you'll need to allow for time to go through security and walk down Main Street U.S.A. toward
Be Our Guest Restaurant.
If I had an 8:25 am breakfast reservation in the Magic Kingdom on a day that the park opened at 9 am, I would arrange for an inexpensive private car service to pick me up at 7:15 am at my resort and ask to be dropped off at Bay Lake Tower at Disney's Contemporary Resort. Then you could take a short walk over to the Magic Kingdom. In this scenario, you would have a bit more control over your arrival time at the Magic Kingdom since you wouldn't have to worry when the next bus would arrive. I tend to err on the side of arriving early for Disney reservations so that I can fully enjoy the experience without undue stress.
Wishing you many magical memories next week,
Jill