I just read Piura will have a usual Winter, after 10 years. So no rains reported anymore, since several weeks. But the impact was, is very strong withing the cities, towns and farms, and reconstruction in all the región will take several months.
PromPerú launched a north región tourism campaign this week. So I guess the tourist infraestructure, routes, specially along the beaches, is fine. In fact I just saw pictures of very dirty beaches in Punta Sal, Mancora, Zorritos but no destroyed buildings, as I remember.
No news about delayed flights anymore either. So I guess it's ok to travel to the north.