BOSTON — Electrical crews are scrambling to restore power to parts of eastern Canada and northern New England after an ice storm crept across the region last week. More than 2 million Canadians and over a half million Americans have been without power. Hydro-Quebec officials said it would take as many as 15 days to restore electricity to some areas. Across the border, President Clinton declared a federal state of emergency in parts of upstate New York. Local emergencies were in effect in Vermont, New Hampshire, and Maine.