Running Comps in a small town... when there aren't any.

[Nicholas Caldwell]

I understand when running comps I want to find homes that are as similar as possible to the subject property.

same # beds/baths

+/- 10% sqft

+/- 10 (ish) year built

Sold within 6 months to a year

within roughly <1mile radius

So if I can't find anything within those parameters, what do I expand first? First thought is to extend the time frame. For example, sold within a year to 18 months... I had to go back two years to get anything and even then I couldn't find a single 4/2.5. Closest I could get was 3/2. 

Is there a different rule of thumb for running comps in a rural area or smaller city?

Do I expand my radius? If so how far?

If I simply can't find any usable comps what do I use then? 

Thanks for the help y'all!