If the park opens at 9 AM but EMH begins at 8 AM, then the first seating at Minnie and Friends will be for 8:10 AM. Unless policy has changed since we last did this, then my answer is, yes, you can get a reservation even without having EMH. You will need to enter at the far left gate. There will be a sign saying something about Minnie and Friends breakfast or character dining. A CM will have a clipboard and check that your reservation is listed. Then your passes will be scanned in for the day and you will be free to enter the park and proceed to the restaurant. We have done this on an 8 AM opening day with a 7:10 AM reservation and enjoyed it very much. You should expect to spend 50-70 minutes at your meal.