With my rental i found that the decrease in interest would save me about $370 a month.

Or it could be just a temporary freeze-related issue with the line between the well head and the house not being buried deep enough and freezing or it could be a separate issue: like Jaron said pump issues are more common than wells actually running dry.

I suggest that people simply MOVE-IN to the temporary structure, then WAIT for the city to knock on the door, or send a letter SOME DAY (it could be YEARS). 

Significant rent decreases are rare.It is the speculators that have the most risk in a downturn.  

If the property fits and we like the numbers it wont matter if there's a dip in the market and the value decreases since we're owning long term and eventually it will come back. 

What’s the general rule of thumb on this particular temporary expense? 

the cost of refinancing will eat up the savings in interest rate.Here's a good article on the decrease in the Fed rate. 

Regarding the decrease in rates by the fed, the 50 bps doesn't necessarily translate into a reduction in mortgage interest rates by half a point. 

My intention is to understand the trending areas within the country and the factors that are motivating the population increases/decreases throughout the nation.  

If we reduce leverage we may get lower cash returns however we do increase our ability to 'stay in the game' and not be forced sellers should rental rates decrease or vacancies rise.