Don't know if you are locked into Stratton, but my pick for the best mountain in sounthern/central Vermont for families with young kids is Pico. Less expensive than the major resorts, tons of easy groomed trails, all trails lead to the same place, large "brown bag" room, lots of free bag storage, etc. There is also the Pico Ski Cl;ub with their own clubhouse right at the base. And while a midsized ski area, it has over 1900 ft of vertical and some of the best classic New England expert trails off the summit.