I basically have a separate system in my garage. Since the streamer/server in my main system uses Roon and we have a mesh router system, I have a mesh node in the garage connected by Ethernet to a Roon endpoint then a DAC with volume control going directly into monoblocks that power three sets of speakers, one set by the pool area, another in a large covered back porch area, and a third inside the garage. The speakers are hard wired and I have not added a sub.
I was smart (or lazy) enough to hang on to my Rotel speaker selector (see below), which compensates for impedance changes resulting from running multiple speakers and allows me to choose any combination of the three sets of speakers.
This year, I replaced my 20-year old Speakercraft/Weathercraft speakers with Bogen/Near A8T, 8-inch Indoor/Outdoor Speakers and have been very pleased with the improvement.