If the building has gas heat then obviously they're not using oil for heating, but you can see if you see any odd, old looking pipes (not water, not gas, pretty narrow and often bent at less than 90 degree angles) going underground.

Specifically, you could narrow the searches down to similar properties as yours.  

I haven't pinned down where exactly I'll be living but I have narrowed to Kennesaw, Acworth, or Dallas.

We use listsource.com primarily to search for leads because we are able to target a certain area and narrow down the results based on specific criteria such as bedroom count, equity %, median price range, etc. 

@Jaren WoeppelThat helps to narrow down the options you have with your parent's 401k.

Have you started narrowing down your search, or are you in your research phase?

My suggestion is to narrow down further to one market.

There are some very very narrow exceptions to this including medical or job transfer.  

Narrowing down your focus as much as possible.

If someone wants to share their opinions on ways to narrow down / categorize / filter the parcel list using public data sources, I'd be happy to share my thoughts on the technical feasibility.