I booked all my fast passes this morning and had no problem getting FoP for the days I wanted. On my 60+2 day, I booked Navi, but I was just playing around earlier this afternoon, and there were still times available for FoP and I was surprised. I was only checking for 4, but there were multiple slots available. As long as you have a 60 day window, I think you should first try for 7, before trying to split them.