It is all integrated with my thermostats, security system and air conditioning.

One thing that is cheap to do is to purchase Braeburn landlord thermostats.

I believe they have a subscription system however from what I recall it's a little bit expensive and is not very user friendly.You can pull the public data from the various websites and then go and extrapolate everything, but unless you've got a pretty good programmer who can build out some engines to go scrape everything you will end up doing a lot of that mining manually.

If you use option 2 there will be only 1 thermostat to decide the temperature, so it will probably need to be in the master bedroom. 

If you're looking to reduce the utilities only low flow faucets and shower headsdual flush toiletslower the temp on the water heater.Make sure the HVAC filter is changed monthlyPreset thermostat.

Easy to solve: either add a programmable t-stat, or you can add a vent-less gas wall heater to bring the temp up quickly and cheaply, then let the electric take over on "cruise control". 

Don’t crank up the thermostat every time your real estate investment gets a little chilly.

.- water efficient heads- Chicago controls thermostats- coin op laundry was our move this year- big ticket item but I am still a kid when I empty the quarters 👍 - make room for parking on the property- additional $- turn the boiler down.

Another thing to consider is you can purchase a thermostat controlled plug/switch that can alleviate anyone having to switch on and off the heat source.

Your county building dept will have physical requirements for a separate dwelling unit (such as thermostatic control, accessibility to the breaker box, basement window egress and fire separation.