Bests & Worsts Reviews from Amazon

I own a number of these(4 actually). Generally they work fine, until today (1/30/2019). In the fall, I installed one of these in my parents cabin up North along with a US Cellular WiFi HotSpot so we could 1) turn up the temp from home before heading there and 2) to monitor the temp in the winter with the App and use the email alerts if the temp went too low or too high. We set the winter temp to 45 degrees to keep pipes from freezing the set the low temp alert (you do this on the website) at 43 degrees. Today we got the alert email at 1am saying the temp was at or below 43 degrees. When I checked my phone app at 5am, it said "Heat On" and 40 degrees. Ok, no problem. Or was there? As the day went on, I expected the temp to drop more if the furnace was not actually working, or to start rising if it was... But Noooooooooo.... it just sat at 40 degrees! I started to get suspicious... It was -15F out at the time, so I took one of my other units, powered it and set it outside. Guess what!?! It stops reporting actual temperature at 40F, and it just stays there! No "---" or real temp. I drove up and sure enough, it was 28 degrees inside the some water had already started freezing. The furnace problem was just a blocked vent pipe from a snow drift - 5 seconds to fix, but we had bad information all day long from this Thermostat!! Now I get that sometimes a T-Stat might have a lowest set-point of 40F, but it should always read and display the actual temp, or if the hardware is too poorly designed (it is not, it is poor software), then it should display dashes "---" or "too low" or SOMETHING to tell us the T-Stat is too stupid to give us true information. This is a major design flaw and I strongly recommend you go with something else - its not worth the frozen pipes!!!!