I wore one several trips ago--we averaged over 20 miles/day! Our longest days were at EPCOT when we usually walk around the Boardwalk and DTD after Illuminations. I doubt you would walk this much with kids in tow--maybe someone else can help you out with that if you're interested. This was a summer trip; I bet it's about the same for our winter trips because we can walk more during the winter since it's cooler, but the parks close earlier. Have fun, and let us know your results! =)