If the landlord insulates, replaces windows, installs smart thermostats, and installs an energy efficient heating system the increase in value might well allow for a refi as long as the rents still support the new loan.

The seller wants to sell as-is because he's getting old and doesn't have the energy or motivation to fix things up -- but fortunately it's been well-maintained. 

There is no magic bullet other than putting in the hours and making it happen!

This is a nice reminder to focus and put energy toward marketing.

Many municipalities/utility providers are offering rebates on water heaters and other energy using products to help offset the cost of replacement. 

The biggest gotchas might be if the ceiling is low or the room(s) don't meet minimum size/geometry requirements,  the building requires a fire sprinkler system and that unit doesn't have one,  or if the city decides the unit must meet some kind of energy efficiency standards.   

So if you don’t have the time and energy to take on a second job (which it inevitably becomes even just viewing and analyzing properties, making offers, etc. never mind once you actually own it and then the real work begins), I would honestly just stick with something truly passive like syndications, REITs, or plain old high dividend yield aristocrat stocks/ mutual funds, vanguard, SPDR etc.  

The energy sector is the driver which will be hitting some speed bumps here soon. 

Plus if the property was in a bad energy consumption shape and being repaired by buyer, government will reduce big part of transaction cost.

What I shared of the OA was just some of the big bullet points but its like 4 pages long.