Without an approved I-526 petition, it may be difficult to request USCIS to afford deference to a portion of the first filing (though it won’t hurt to ask). Either way, if the denial was not based on your source of funds you can at least use the same information and documentation. Unfortunately, processing times are hard to guarantee, even with the USCIS estimates being available.
You can refile an I-526 petition with a different project and a new investment fund amount.