We have a similar set-up in mind, however I worry about the climatic conditions created inside this plastic pot and whether it will reflect soil surface temperature (which we are interested in).
I would have prefered to place loggers directly in the soil, but I think these "Hobo pro v2" (which is what I have) are not robust enough.
In my search for info on loggers, I found, I have colleagues using "GeoPrecision"- or "Lascar"-loggers directly in soil, and I found papers describing the use of the "Hobo pro waterproof"-model for the same thing.
I have used it for 20 months and I buried it around 10 cm. it begun September to May ( 2 winter ) and it was ok. I used it in hyrcanian forest in North of Iran.we hand aronud 50 cm snow in winter .
I used a temperature sensor (HOBO UTBI-001 TidbiT v2, Onset Computer Corporation, U.S.) to record soil temperature at 5 cm depth for 28 months in subtropical China. The sensor worked well. Our data has been pulished this year as bellow:
Wang Y, Wang H*, Xu M, Ma Z, Wang Z-L. 2015. Soil organic carbon stocks and CO2 effluxes of native and exotic pine plantations in subtropical China. Catena, 128: 167–173. doi:10.1016/j.catena.2015.02.003
My cohort uses HOBO pendant sensors quite extensively to record soil temperature in our agricultural research plots. They are smaller and less expensive that the pro v2. First we make a electronic document that has a list of the serial numbers of all of the loggers, and which plot they will be placed in. Secondly we put the loggers in a small plastic bag and label the bag with the plot number. The bag protects the logger from getting scuffed and scratched during installation. When instilling the sensors in the field we want to minimize soil disturbance. We install our sensor to a depth of 6 in, and we use a wooden stick to do so. We press the stick into the ground 4 in deep, then place the sensor into the hole we just created. Using the same stuck we force the sensor into the soil another 2 inches, and fill the hole back in. The method is quite crude but has served us well. Lastly, you need to mark the exact location of the sensor. I cannot stress this enough. I spent hours meticulouly digging through my plot like an archeologist looking for sensors because I did not mark the location well. I suggest small flags. I hope this help.