Hi Erica!
Thank you for bringing your question to the Disney Parks Moms Panel!
This sounds like a great trip! In 2010, we brought 23 family members to the
Princess Half Marathon and it was a blast.
You have a lot of options for larger groups. I recommend following
this link to information on rooms for bigger parties. I do recommend staying at one of the Walt Disney World Resorts, though. Each resort offers complimentary bus transportation to and from each race weekend event for runners and spectators. This is a huge benefit to staying on property.
Personally, my family loves the
Disney Dining Plan. But, we have two teenage boys whose main focus of going to Disney World is where they want to eat. If you plan to do character dining and eat at some of the nicer table service restaurants, then I think it's a good deal. If not, then it probably won't save you any money. My favorite part about using the dining plan is that it's paid for in advance. That way, I don't feel like I am constantly shelling out money for food. I feel like it's a great choice if you plan ahead and use your credits wisely.
I hope this helps! Please let me know if you have any other questions.