Hi Alison! Welcome back to the Disney Parks Moms Panel!
It sounds like you have your thinking cap on and are planning out the details of your upcoming vacation to the Walt Disney World Resort. I do the same thing, especially since I don't want to feel rushed or stressed thinking that I might miss my dining reservation!
I have never had any trouble getting in a little early for my breakfast dining reservations. The Cast Members at the breakfast entrance line know that it is little bit of a walk to
Akershus Royal Banquet Hall in World Showcase from
Epcot's entrance, and I have always found them to be understanding when I arrive early. Personally, I would probably try to arrive around 8:30 a.m. Most likely, you will be allowed in at that time, but even if you had to wait, it wouldn't be for very long. Early breakfast reservations are a great time to take a few quick pictures in a less crowded theme park, so make sure to have your camera out and ready!
Enjoy your visit, Alison! Happy eating!
Tabitha