Given a large n-ary tree where the root node can pass information to one child per iteration, and in subsequent iterations, nodes can pass information to one child while the root continues with others, find the minimum number of iterations to reach all nodes.

This problem can be solved by determining the height of the n-ary tree. The minimum number of iterations required to reach all nodes is equivalent to the height of the tree. We can calculate the height using a Breadth-First Search (BFS) or Depth-First Search (DFS) approach. During the traversal, we keep track of the maximum depth reached. The height of the tree is the maximum depth from the root to any leaf node. Since information can be passed to one child per iteration, the time taken to reach the deepest node will dictate the total number of iterations needed to propagate information to all nodes.