did you actually put the Visonic (which model MCT-340? ) in the freezer and it stopped reporting less than -1.6F? That would be good to know.
The Centralite multi-sensors, Smartthings relabelled, circa 2016, take 2x AAAA (unusual), read down to at least -9F and up to 140F . They are probably a little rare now, but the Centrallite/Smartthings Open-Close Sensors also read temperature and seem to perform the same
I would avoid the newer generation# STS-MLT-250 , I had too many problems.
I see one of the old preferred first gen types on ebay,
otherwise I would try whatever you have lying around. These devices frequently operate outside of their printed ratings anyway. If it’s really important then put in a couple different ones.
