Similar green energy investments could be considered if you can make the numbers work (credits on some types of low income housing can be north of 50%).Depending on how long these properties have been held, they could consider implementing cost segregation studies via a change in accounting method to accelerate some depreciation.The operating proceeds could be re-deployed into new properties where cost segregation is an option to accelerate depreciation to offset proceeds.If the properties are low basis and we are not maximizing the 199A deduction, maybe considering an S-Corp structure for management to be able to participate in retirement plans and also generate wages to use as a 199A base. 

Find Brandon's videos on YouTube for the "four square" method of analyzing homes and practice.

If there's an alternative method that has worked for you, please share. 

It can come from cash, or (my pref) a LOC (not tied to the property).The alternative is a proactive method (my pref).Let's say you have roof that needs to be replaced within the next 5 years. 

My method as well. 

We were initially looking to flip homes, which would potentially bring higher immediate cash returns for her enjoyment in her later years, however I’ve been researching the brrrr method as well to generate cash flow without the stress that flip process may cause her.

@Shai Galapo two methods I would suggest here.  

If you want to gather emails and do some email marketing, there's a new company that many hosts have been pretty happy with....Go STR MarketingI will check into this company. i don't think this will be a substitute for StayFI as you still need a better method of capturing data beyond just the contact date you get from your PMS.

Using the next ten years and the snowball method to pay them off.

Not sure if this is the most recent post on land flipping,  but I came across another ed platform -  The Land Method and Land Riches Blueprint.