Often when a landlord does not live near some of their rental property they will hire a real estate agent to act as the property manager or rental agent. READ the rental agreement very carefully. They are written to benefit the landlord. To protect yourself take pictures of EVERY room before you occupy the cabin, and demand a walk through inspection just before you leave to reduce your risk of being charged for damage or cleaning fees.
Certainly, they can have it for sale and still rent it. The owner probably bought it so they could make money renting it, and rentals probably aren t enough to pay their mortgage.