Not applying to enough PhD programs?

Hi all! I've just finalized my list and gathered all my application materials. I just asked professors for letters of rec last night, and 2 have already said yes; however, one of them asked if I was sure about where I'm applying and if I "should throw another few on there, since the schools are picky."

I'm applying to 5 PhD programs for Creative Writing, and there aren't many other fully-funded CRW PhD programs in great locations (something important to me). Also, the thing is, one of these schools is where I went to undergrad, and 2/3 of the profs who've agreed to write me letters of rec are esteemed professors at the school & in the grad program, too.

The prof who suggested this is older (he's nearly 80) and he's kind of known for offering unsolicited advice in the way most dads/grandpas/etc. do. I've already finalized my list and think of the 5, only 2 are proper "reaches." (I also can't really afford to apply to more than 5.)

Should I really be applying to more? Or should I take his advice with a grain of salt? Sorry this is so long - any insight would be appreciated x