We usually do 2 mugs for our family of 4, dh and I get coffee in the morning and then the kids will use them for lemonade at pool time as well as when we are eating in the food court.
DH and DD's don't drink soda so they will choose milk, juice etc. not offered in the refill machines.
We always hit the grocery store to keep soda, juice and water in the room. Just keep a cooler or keep the drinks warm and keep the ice bucket filled to chill drinks one at at time.
TJ