There are loads of 'put them in the fridge/freezer' temp sensors out there, made just for this. I did buy lithium AA batteries (which work down to -40C even) for the sensor end.
My thoughts are, these things are special built, and only wake every few minutes or so to burst send. Batteries tend to last a couple of years (but with the lithium ones!), and I get beeeeps from the receiver if it dies.
(Not knocking your solution, it gives you more flexibility)
I saw a few that were wired with cords that seemed more intrusive than the telephone cord I tried, so I went my own way. And most of them didn't seem to be something I could connect to Home Assistant.
Well amazon has endless examples of wireless working fine. However, as I said, you get more flexibility with your own solution (like using Home Assistant)
My thoughts are, these things are special built, and only wake every few minutes or so to burst send. Batteries tend to last a couple of years (but with the lithium ones!), and I get beeeeps from the receiver if it dies.
(Not knocking your solution, it gives you more flexibility)