Big ground takes a different kind of night. Out toward the Route 190 interchange the lots run wide and open, and when a blizzard settles over Leominster, N.E. Acreage Group, Inc. is out pushing snow into piles that will still be sitting there in March. Plowing, walkway clearing, sanding and salting — the whole job, done in the hours nobody watches. Morning comes, the pavement is black, and the doors open on time. Leominster is the base, with Sterling, Lancaster, Lunenburg and Fitchburg in the territory.