Worse-case scenario is that you have a higher tax bill this year from the additional income, but a lower tax bill next year from the reduction in income (since half of the year's income was recognized the year before).

When analyzing a property I put the rent reduction into the numbers before buying.  

If you can negotiate with the seller that the seller either get them out, or subsidizes the difference in rent you need with a price reduction that will get you through the end of their leases and into spring? 

I believe if the kids are living there it would be considered a personal benefit to you, a reduction in alimony, etc. would make it a prohibited transaction. 

My goal would be to automate communications, but also to manage all the calendars in one place, have automatic price reductions as vacant dates approach, and to be listed on additional sites other than Airbnb and VRBO. 

Bottom line I offered him a $50 reduction for the next month to hopefully resolve the matter.

And under offer them a rent reduction or an upgrade on an appliance or fixture of their choice within a certain  budget. 

if there are 500 available and none are selling, you will likely need a price reduction to generate interest.

Or they want a rent reduction. 

If you want to update the place you could do it at your own expense (considering the good advice from other investors above) and give notice to the tenants of a future rent increase in accordance with your lease agreement and applicable law where the property is located; pay now and charge higher rents on your next lease; allow tenants to pay and deduct the expense from the rent as a reduction in rent payments for the next 4 months or whatever you decide, etc... etc... several ways to structure it.