However, how about landscaping, snow removal, pest control, advertising, accounting costs?

For example, if they had rented from me with no problems for 5 years I'd probably advertise the place for rent asap and help these tenants by forgiving the rent owed if they "cleaned up very well" and moved out in 30 days, but I would have told them that the first week they were late.   

You're not advertising a security or soliciting for a specific deal so engaging a security attorney at this point isn't necessarily required.  

They seemed to have forgotten that this is a customer service industry and people expect what you are advertising and spend  a lot of time and money to find a place they would like to stay for a well deserved vacation.

However, many other functions require a license, such as advertising and maintenance.Although an agreement/contract can theoretically be made for a limited scope of work so that no license is required, it may be very difficult to maintain (especially with family and friends!).

we had a rehab to be done in a pinch , they came thru as advertised. 

Sending out targeted direct mail and advertising may be the way to go first. 

Advertise the rental.

I start advertising for the next tenant to begin a lease the day after the fix term lease, which has just been signed, ends.

If you advertise the extra beds as free/bonus, I wouldn't change your format.