(These are houses not apartments or condos)  my average tennant is currently over 5 years and I had my first vacancy this month due to covid in over 3 years.

One of those risks which many hosts should have taken into consideration is higher vacancy.

The other thought I have is to renew with a Month To Month lease and monitor their behavior so I wouldn’t have to try to fill a vacancy in these times and I believe the tenants are probably good people (teachers) that might have just hit a rough turn?

Tile and laminate flooringOccupied by tenants who are paying 1800/month each and pay all utilities and take care of yard maintenance.Landlord pays water/sewer which is 190/monthIm thinking of offering 450k with a 20% down payment in cash of around 90000-100000 and carrying a 30 year loan with a mortgage payment of around 2075/month (tax and insurance included).It seems it would cash flow 1525 a month before accounting for maintenance, capex, and vacancy percentages.Am I calculating this right?  

I also use them during vacancy turnovers since those turnovers are fully automated, self-serve showings, but you have to have a way to ensure batteries get swapped out regularly, then run a separate cellular network to push updates to the locks over time, which is a another added cost.

The goal was to fill vacancies as fast as we could, while also increasing the curb appeal.

It certainly is an option to turn the units into long term rental if you own just a few.Perhaps the only option.Many of these businesses with 100s of apartment units solely on the Air BnB model will suddenly be dealing with monster vacancies all at once though.It's not at all easy to go from zero to full occupancy in the current market.And tenants may soon begin to default on rent even on longer term leases.Coupled with all the creative financing that makes a scaled larger Air BnB portfolio possible, it's a perfect storm.

Then you have to renovate for an additional $135,000 and sit on a vacancy for another X months.

The true economic (possibly physical) vacancy rateTo hedge this, I'm stress testing deal analysis with 10-15% (at least) off the ARV and rents and doubling vacancy. 

Then figure out how much it costs to keep that house with repairs vacancy and mortgage payments to see if there is a return on investment.