He does this for mine for a low flat monthly fee and he really helps fill up the weekdays/off seasons and optimize booking revenue during the peak times.

DSCR requires No income, No Taxes and Commercial requires a PFS, occupancy ratios usually above (90%), Credit scores above 720+ much higher assets for (PITI reserves and overall risk, landlord seasoning, and more.A Heloc can be used in most cases for anything but when you are trying to buy a commercial building which is higher risk, the committee/UW can and in most cases will deny it if they feel you are over extended low assets or with no landlord experience, unless you have a meaty amount of equity to cross collateralize for a junior lien on another property.

On the other hand, the tenant may be more likely to move to a different apartment since there are more options on the market and they could find a better fit.I think you can make an argument that it's actually better to have leases expire in "slower" or less desirable moving seasons like the fall and winter.

The first floor is rented out to a seasonal business, they pay year round, $1000 a month.

With the season in Sarasota County considered November - April, what is the best way to market the property as a Medium Term Rental (at least 30 days)? 

There is no requirement that the funds need to be seasoned.

It currently is a sunroom/3 seasons room.  

We also have no seasoning products that would allow you to pull some cash out if that made sense for you. 

We actually recommend MTR to the owners of the properties we manage during the winter months, because of the seasonality in Indy.

David,Reach out to @Lucia Rushton I have worked with Lucia several times and as a seasoned agent she has an a solid track record of finding good cash flowing STR's.