not the parks, not restaurants.
At some resorts Pool bars - yes
Most resorts that have a food court - thats where you refill - some people are savvy and take their mugs fill the, get on the bus. Pack them in backpacks, return from a day at the park, let out at the food court area - fill mug!
(moreoften than not, I forget to take a mug, so I have to go all the way to our room then all the way back to get my mug filled!)