I don't quite understand this. It's a long road to the iron, and the border pop takes 5 turns.
Would you spend three turns each building a road north of the horses, north of the city, and on the iron? An extra two turns, building roads on the deer, deer-NE, city-N and iron? Or will the new city be on the coast instead, so that it's automatically connected to our trade network? The worker logistics aren't easy - the Orleans worker struggles to be in the right place at the right time so I'm tempted to build the longer road which we'll need anyway to hook up the deer.