Right on... So far, I've had zero issues with any smart gadgets out in my detached garage in terms of extreme temperature failures etc, so even though your attached space is unconditioned, you should still not get the full extremes a detached structure has to deal with. That's good news!
For any battery-powered smart stuff out in my garage, I buy only devices that can take AA or AAA batts, and then use a Lenink battery conversion kit (like this) to power it... They work freakin' awesome, and have a ultra-thin cable that's worked perfect with every device casing I've encountered so far.
I have those kits for my Hue indoor motion sensor out there, a Third Reality (3R) service-door contact sensor, and a 3R switch I use to control power to my bay lights (more on that later). Though it took some creative wire splicing, I even use one to power my Hue outdoor sensor for the back yard.
Powering all that means having outlets conveniently accessible, but since my detached garage is all unfinished (minus one drywalled wall required by code), it's easy for me to run new wires wherever I need them, and I don't have to be overly concerned about making sure it's all super pretty.
I have a Casete repeater in the garage to ensure coverage to a couple nearby Caseta outdoor plugs, and I have a couple power-monitoring smart plugs for a window fan and battery tender out there -- one Aeotec Smart Switch 7 and one Innr plug.
I use a Zen17 for GDO control, but I hard-wired 2 dumb reed sensors to it for door position instead of using a tilt sensor (to avoid batteries). That setup has been flawless -- no misfires at all since installing.
Up in the rafters and pointed at the house, I have an Aeotec RE7 and another Innr smart plug -- these are my main house-to-garage ZW and ZB repeaters respectively.
I have a non-integrated Wyze cam inside the garage by where most tools are -- it just loops its own SD card -- I'm not paying extra for any fancy detection/alert features. It was a cheap buy and I've been happy with its performance.
GD and service door contact sensors are set to alert if opened when no one's home, late at night etc , and same for the Hue indoor sensor (it would catch a window entry). That alert would prompt me to look at the Wyze cam, so that's all good enough for me.
My main swath of indoor lighting is wired to a Zen71 switch by the service door, but I have 3 separate shop lights (1 over each bay and 1 near my workbench) that are controlled by a dumb ceiling mounted motion sensor (RAB brand) centered in the garage. That setup gives plenty of hands-free light for basic comings-&-goings and quick trips out to grab something.
Up by the RAB sensor, I wired a dumb 3-way switch backwards so that I can power those 3 lights either thru the RAB (normal setting) or I can apply direct power to them for times when I need ALL lights on out there but am doing low-movement work that doesn't keep the RAB sensor triggered.
I mounted the 3R switch over that backward-wired 3-way dumb switch -- that way I can just double-tap the Zen71 switch's upper paddle to command the 3R to activate constant power to those shop lights when I need it. When I tap the lower paddle, it checks to see if the 3R switch is in the constant-power position, and if so, it flips it back to the normal RAB-controlled switch position for the 3 shop-lights.
It may not all be super pretty to look at, but you can have a MN-proof (no battery) smart garage! 