If you are looking for a wireless control option (e.g., smartphone controllable) the Sonos Amp could be what you would need. You could put it in another room and run a speaker wire to your garage, or find a space in the garage out of the way. It is small. 125wpc. I use one for a pair of patio speakers and another for a ceiling system in my house, and still another at an office where the amp is tucked away in the cage with my network switches and other gear. The app is well designed.

Check out the Fosi BT20A for a hundred bucks on Amazon. Has plenty of power and you can stream to it.

Thanks all, some great suggestions. I did start thinking of a sound bar too given I have less space to work with after having the garage redone.

Or perhaps wait for the WiiM pro to come out, wasn't looking for a crazy setup but enjoy good music while I'm out there!

I found a older NAD T760 off craigslist for like $75.  Works great fro my purpose. 

Sorry, forgot to add, I can stream anything to the soundbar via Bluetooth.....

I have been using a repurposed soundbar with a sub in my garage for years. (Philly area) Considering the potential for heat and humidity, this to me was a no brainer.

"Honey, are you down there?"

features: mute, remote volume, balance ...... pause 

In my shop I have a pair of Ascend acoustics old CBM 170s I bought 20 years ago mounted in the corners.. powered by a ATI 1202 amplifier I had laying around, and I bought a Audioengine B1 Bluetooth receiver going to the amp that has a decent DAC chip in it on Amazon for like $190

It sounds really good and I just use my phone to control everything like a Bluetooth speaker, really simple and those Bluetooth receivers have great range, I can go probably 40-50 feet maybe more. And nothing to control, just use Qobuz, or YouTube or whatever is in my phone

Check out the PS audio Sprout 100.

Keep it simple if you have WiFi  access.

PSB Alpha iQ Streaming Powered Speakers with BluOS (Pair)

1000$ 

SVS Soundbase ($600 open box) - mixed review though

Wiim amp ($300) - mixed review too but for a garage no brainer; You might want to wait for Wiim amp Pro version which is supposed to fix most of the cons;

The Wiim Pro Plus + Fosi V3 stack ($235) - sound better, punchier and more dynamics than Wiim amp

The wiim amp is a vg option

REGA BRIO