We only have crown molding in our foyer, and adjacent living room and dining room. The LR/DR is one large room separated by pillars. The foyer leads up to the 2nd floor hall, which also has the same crown molding since its as if its the same room. Don't think you need to do all rooms. Will watch to see what others suggest

Thanks, also does my crown molding need to match by baseboards?

It is fine to leave the crown moulding out in less trafficked rooms or simply installed in one main room. I recommend unifying the wood trim in the home with the same color. Baseboards are white? So is the window and door casing? Then so follows the crown moulding.

Totally agree with Ironwood.