I don't believe there is a magic number. 

Some low margin consumer electronics are just not economical at this time to source from other countries, China had the magic formula of cost and quality - per a warehouse tenant of mine.

This is what brought us a DOW near 30k vs 2005 at just 10k, there wasn't 3X the commerce and wealth last year vs 2005, not 3x the people working nor 3x the earnings, it is the joy and magic of inflation. 

With that said, just because the landlord is under no obligation to do anything other than act in a timely manner (landlords can't predict the future and don't have a magic wand) it doesn't mean the landlord can't offer a rent discount for the inconvenience however, this is a courtesy and a personal decision. 

There is no magic bullet.

@Matthew Otero - Once you reach that magical cash flow number, do you think you will bounce on your W2 job?

Of course if we magically return to where we were then we will be where we were, but I don't see that happening.Owning still makes a ton of sense.

These countertops are magical.

@Ladè BaruwaBe careful of spreadsheet magic.

I suppose I would get buddy-buddy with someone who has power to make paper do magical things.Might the city or county work with you to evacuate these squatters because of , say, fire code violations?