I saw a prior post of yours on being to Epcot many times, so you’d likely be the best judge of that… it depends on several variables, including your actual arrival time to the park, true speed of walking, crowd size that you’d have to get through, etc… Of note, given where Easter falls this year, I don’t think many school-aged kids will be on family vacation that day, so hopefully appreciably lighter crowds that early in the day.
As you’re likely aware, Epcot is quite large and:
1.) If you are staying at one of various hotels that offer early entry (8:30am), take advantage of it.
2.) If not, still consider getting there a bit early, to be near the front of the pack.
3.) And if you get there early, even without early entry, you may be able to walk a bit of the distance before the park officially opens.
4.) Regardless, they rent electric chairs, which may help for not only catching the parade but also the day in general.
5.) Canada is the nearest country to the main entrance.
6.) Google Maps indicates it’s a 0.4 mile / 8 minute walk from Spaceship Earth to Canada pavilion. In my experience with their estimated walking times, it presumes a pretty decent clip and no crowds to zig-zag through.
Beyond this, I think but am not positive that the band parades end around the International Gateway entrance to the park. So based on your particulars, showing up at the finish line as opposed to the starting line could buy you a couple of extra minutes.
Hope March 7th is a special day for your family!