I think the answer is going to depend on your layout, what rooms you’re likely going to want to play together and which ones are unlikely.  For example your main living areas, master bedroom and bath should be in the same system.  I’d include outdoors.  Guest bedrooms, maybe workout room, office, things like that could go in a second separate system.

Also worth noting that if you’re doing in ceiling Sonance speakers (or other passive speakers), those do not count in the total to 32.  Only the amp would count.  So if  you have a large room with multiple speakers, or an outdoor environment, you can use 1 amp with 2 pair of speakers.  A very large room could use a Port, 3rd party amp, and whatever speakers that drives..counting as 1.