Winter temperature monitoring under protective cover

Last winter I lost most of my persimmon despite several layers of covers. This year I am going to add heat lamp and really insulating cover. But to prevent overheating I want to use thermostat to regulate the temperature automatically. The thermostat will be located under the cover and I will not have a way to check if it is still working (yes, I do not trust those things much!) So I want to use the additional thermometer with probe under the cover, and display outside of it to check from time to time. Wireless will not work - Reflective insulation doesn’t let signal through( Tested in my spring greenhouse). My problem is, I can’t find any thermometer that would have display part rated for outside or have probe cable long enough(like 30’) to get onto the house. I can protect display from rain/snow, but not from the cold or high humidity. Does anybody know if such devices exist?

Does the insulating material need to be the reflective type?A little electric heater with thermostat and fan,inside something like a tarp,over a frame,will probably allow a radio signal to go through it.
One of the drawbacks,might be the cost of energy for the Winter,but that might not be too much to keep it above freezing. Brady

Insulated material doesn’t have to be reflective, it is just what is easier to install. Tarp doesn’t help much if it doesn’t have insulator, the heater will be running all the time. This is how it is in my spring greenhouse, too expensive to heat.

Another way to do it,is cut a small window and cover that with clear thick plastic.Then hang a thermometer inside,viewable from the cutout.Brady

Thanks!

I think I found a solution - looks like I do not need thermometer after all.
This digital controller can work! Inkbird Itc-308
Ambient Temperature: -30~ 75 ° C / -22~ 167 ° F
Temperature Control Range : -50~99 °C / -58~210 ° F
Sensor Length: 2m / 6.56ft

So I can put sensor in covered enclosure, and device itself outside of enclosure and cover it from snow/rain. May be put it in sealed plastic bag to control humidity. This way I will see if it is still working OK.

That may do it and not too expensive. Brady