With all of the new home automation stuff available now there are lots of options, if you have an internet connection. There are some neat long range (miles) wireless bridge products (google Ubiquiti NanoBeam) to extend a wifi network, but they generally need line of sight and I'm not wild about mounting an antenna on the roof of the hangar.
Then I stumbled onto an LTE mobile hotspot called the Karma Go. It uses the Sprint cell data network, and creates it's own wifi network. They have different data plans, but I'm using the least expensive which is $10/mo for 1 GB of data. On top of that I'm paying an additional $5/mo for what they call premium services, which allows me to create a custom SSID and password so the wifi thermostat (or any type of headless device) can connect. So, $15/mo for 1 GB of data, month to month with no contracts. My only reservation was whether or not it would get a good enough cell signal inside the metal hangar, but that has not been an issue so far.
The old mechanical thermostat was replaced with a Honeywell RTH6580WF wifi themostat, in conjunction with an Aube Technologies RC840T-120 relay transformer to control the heater and provide 24V AC to power the thermostat. It's been working great for a few days, now the only question is long term reliability. The Honeywell thermostat has a nice android/iOS app that makes it really easy to monitor the hangar temp and control the system from anywhere. Now I'll be able to leave the heater off most of the time. When I know I'm going to fly, I'll turn the heat on for a while (how long depends on ambient temps, but no more than a day prior seems to get the oil and TIT temps up to the indoor temp set point of 45* F) without having to make an extra trip to the airport.
If you have electric engine preheat you could add a wifi outlet to remotely control preheat. Really, once you have wifi in the hangar the options now are endless.



