My Viper alarm with remote start has a 2 way remote with temperature monitoring function. You can enable "smart start" mode and it will start the motor whenever the temperature is above a certain level, below a certain level, or the battery voltage falls below a certain level.
It also send cabin temperature reports to the smart remote.
You do have to keep the temperature controls set appropriately for heat / AC - all it does is start and run the motor so it is up to you to have things set right.
Thanks for the info guys! I'll definitely look into the Viper and Compustar systems. The DEI model I found on the internet is no longer available and I couldn't find any other manufacturers that had them.
2005 E350 Chateau - V10 - Agile Offroad 4x4
2012 CTS-V Wagon - For the baby...