Septemberclaver housed several motorcycles, a car, a truck, and a helicopter. Only the Systems Operator piloted the helicopter. If Clara's father came after her, he would probably take a motorcycle, but from Septemberlaver, he could only get as far as the NorthWest corner of the lake. No road circled the lake. From where he'd have to park the motorcycle, it would take several hours to hike to the cabin.
Of course, if he had access to a boat he could be there much sooner. Nevertheless, there was time to make a deviled ham sandwich and explore the secret bedroom.