Hi Kathleen!
Welcome to the Disney Parks Moms Panel! I am a big fan of the refillable resort mugs and we purchase them on every trip. Not only does it remind me to drink enough, but it also makes a great souvenir to bring home.
We commonly do a split stay and have even done up to three resorts in one trip! You are absolutely able to use your resort refillable mug for all nine days of your stay across both resorts. In fact, you can use your refillable mug at any Walt Disney World Resort Hotel refill station during your stay up to 14 days!
This can be a great tip to know if you will be visiting any other resorts. For example, if you’re looking for a quick-service lunch break near Epcot, walk out the International Gateway to Disney's Beach Club Resort and have lunch at the
Beach Club Marketplace. You can order an entree, and instead of purchasing a beverage with your meal, you simply refill your mug! If you are on the Disney Dining Plan which includes a beverage, grab a bottled beverage to enjoy later.
Here's my other expert tip, while you cannot refill your mugs within the theme parks, I like to ask for a complimentary glass of ice water from quick-service dining locations, and then transfer it to my refill mug to keep my water cold as I explore the parks.
So bring that refill mug with you Kathleen, and have a happy and hydrated visit to the Walt Disney World Resort!
- Kate