To avoid harming the homeowner's grass and landscaping, may my firm fold up the plastic sheeting used for containment at night and re-use it the next day?

Yes, as long as your firm does so in a way that contains any dust and debris on the plastic. One way to accomplish this is to collect and remove the paint chips and debris from the plastic sheeting at the end of each day, mist the sheeting and fold it dirty side inward.