The answer may depend on the field you happen to be working in. As an example, in health sciences, 5 months is an extremely short amount of time. It takes years until you have any data that's worth publishing and as a junior scientist, it is rare to publish ideas or concepts alone (ie. writing a review article, letter to the editor etc.). Those articles are usually written by senior scientists in the field who are invited by the journals to do so.
The focus of a junior scientist (at least in health sciences) is expected to be the production and publishing good data. Once you have the data, the priority is to get it peer reviewed and published asap, and when you do so, you do not want to be withholding any data for later. You do not want to make a hodgepodge as Dr. Buffy said, but in order to get a high impact paper, you want your paper to be rich in content.
A paper that is rich in content gets a lot of citations, not only for the main message that it is conveying, but for the methods employed, individual pieces of data and the occasional reference to new ideas, concepts and possible future research directions (and... you are intending to withhold this?:D). A journal's aim is to maximize its impact factor, so a rich manuscript is the most valuable for them. When you try and divide your content into sub-papers, your main manuscript loses some of its desirability for the high impact journals and the sub-papers will usually be extremely difficult to publish anywhere. Some may never even make it to any journal at all, and the process will drain a lot of time and energy from you.
You also need to take into account the human factor: by the time you successfully published 1 paper, you will be near the end of the road as a PhD student, burnt-out, emotionally drained and depleted. The ideas that once looked great will appear so far away and it is not unusual for individuals to prefer spending time with family (or just some high quality sleep) over pursuing those. I found myself handing some great projects of my own to newcomers of the lab which I never regretted. Most eventually got published and I was the severalth author, but at least they made the finish line. I guess my point is, if you discuss your great ideas with the team now instead of keeping them to yourself:
- You may at least get some credit for the intellectual aspect of the work.
- The ideas may have a better chance at eventually being realized and your name being associated with it.
- You will get criticism, which is great. Some ideas may not be as great as you imagined they were, and may have some room for improvement.
One can't do everything on their own and 21st century science is nothing but teamwork.