How much longer does this railroad have to live?

Likely not long. This has happened to many of these little railroads. They have just enough business to pay their employees and make a modest profit. But sooner (I doubt later) they will have a major maintenance item, such as repair the track (at about $100,000 a mile) which they can't afford and that will be the end of that railroad as it can never generate enough money to pay for the repair.