Publishing something in incremental way or as a single paper by waiting for more time?
Publishing incrementally gives you more feedback from peers as you go. Publishing in a "big bang" way makes preemption more likely since it takes you more time. It would be awful to spend years on a magnum opus only to be beaten to publication by someone else. 

However, your incremental results should be significant enough that they stand on their own. You don't want to get the reputation of publishing trivia. 

The best of all worlds is that you publish a series of important, if small results, that build to the crescendo with the big bang. 

You can also, perhaps, depending on your position, use small (but meaningful) results to introduce newer students to your research and to build a core of researchers in your topic.