You will be better prepared next year when you hopefully have a bigger nest egg to invest.

Install a Nest or Ecobee thermostat along with Bluetooth keyless deadbolt locks. 

In six months or a year (which will fly by when you are working OT) you will have a nice nest egg to start investing.But this unglamorous, not sexy strategy would not make a good podcast or sell a book.   

I’m wondering if a Nest or other “smart” thermostat may be able to provide some type of data output that could then help me in dividing the oil usage between the two tenants??

I think there's a market for something less than a Nest that you program by Bluetooth from your phone.

Abridged list:- Before moving i removed my Nest thermostat, and hired them to install a different one. 

Hopefully one day (as he experiences more & more on his own), he will realize that he has only been angry at himself this whole time, & that we really have done nothing but helped him this whole time (including pushing him out of the nest).Many blessings!

UDirect is a popular option - Many companies do not allow a 401k rollover if you are still employed with them, so check with your HR to make sure it's allowed in your company plan - When using your 401k nest egg, it's imperative that you are with a highly experienced team or syndicate with many demonstrated projects.

State taxes may also apply depending on your state of residence and also a 10% early distribution penalty will apply if you are under age 59 1/2.Bottom line, investing an IRA in promissory notes is simply another way of diversifying your nest egg.

So my recommendation: save, learn, add to the nest age.