You might want to put a timer on the thermostat that turns it up and down depending on time of day or charge them over and above a certain amount of usage. 

Most of the arguments will be over cleaning and stealing food, and wanting space in the kitchen at the same time.I'd also include utilities in the rent, and if you have to put one of those covers with a lock on the thermostat, so be it, but if you do the split the utilities thing, they'll argue about that, too.Just eliminate as many things that will cause arguments as possible, and just do month to month contracts for each separate room, is what I suggest.Because it's really a mess when a group rents and one wants out, or they all want one gone and they can't get rid of them.  

In other words, let's say over the winter the cost of oil to heat tenants who don't care if the thermostat is left on at 80 degrees with the window open - runs $300/month.  

Never need to discuss it, but it's a just-in-case thing.I'd put one of those locks on the thermostat so they can't change the temps for the entire house.  

It has one furnace and one thermostat in the down unit that controls the temperature for the entire house-both units.

When you go over the lease, provide them a tenant instruction sheet with your welcome packet that explains:- how they can pay rent- how to make a repair request- watering restrictions- how to operate unit's HVAC, thermostat, care of garbage disposal, location of main water shut off, gas shut off, breaker box- numbers or links to turn on/transfer utility accounts- how your city enforces noise ordinances and how this may effect those who violate it (BTW, your tenant  blasting his music so it can be heard at by other residents on the block  at 10 am is just as bad as if he is doing it at 4 in the morning). - anything else you feel tenant should knowOthers have given you some great suggestions for collecting rent automatically.

Do I just flat out ask them to reset the thermostat or something or is there a better way?

Everything working as It should.Tenant not satisfied says It only is 62 in apartment and thermostat is at 76. 

We replaced the thermostats with thermostats that max out at 72 degrees.  

I haven't yet targeted specific commuting professionals, but heard a podcast where the investor advertised offering tech packages to attract young professionals: usb outlets, smart doorbell, lighting and thermostat.