Walter Carpenter walks across the ski resort’s dining room on a knee that needs to be replaced and a hip that’s going bad. Lumbering into the kitchen, he deposits a brown bin of dirty dishes on a counter before heading back out to collect more bowls of half-eaten tomato soup and plates littered with sandwich crusts. “One foot in front of the other,” he jokes to kitchen prep worker Kim Hopper, 72, as they pass each other.Carpenter, 69, has worked winters at the Mad River Glen ski area in Waitsfie...