But it is a price the couple are apparently having to pay to achieve their dream of running a restaurant-guest house at the highest and most remote railway station in the UK.
As it is, many passers-by just use their garden anyway in the absence of a WC, while others just want to wait for the train in the Corrour Station House Restaurant situated right beside the famous rail halt.
Corrour is between Rannoch and Tulloch stations on the Glasgow-Fort William line and you can get to it only by train, on foot or by a rough track. The nearest public road is 17 miles away.
Most people will know it from the film Trainspotting as the place where the characters Renton, Tommy, Sick Boy and Spud - played by Ewan McGregor, Kevin McKidd, Jonny Lee Miller and Ewen Bremner, arrive in the great outdoors only for Renton to deliver his "It's s**** being Scottish" speech.
But now Ms MacKenzie and Mr Bennett, both 24, are appealing for help from Network Rail - which owns the station - because about 12,000 journeys are made to and from Corrour annually, particularly by walkers.
At 1339ft above sea level the station provides a convenient starting point for walkers, particularly those doing the nearby Munros (mountains over 3000ft). Yet there are no facilities of any kind at the station.
Ms MacKenzie said: "Our home, Corrour Station House, had previously been operated as a cafe/bunkhouse, which allowed passers by to sit and have a cup of tea whilst waiting for their train.
"However, this business model was unsuitable for such a location and the business failed numerous times."
So when they took over 2012 they opened "a unique restaurant with rooms, as a memorable place to outdoor enthusiasts to base themselves."
They open the restaurant and bar to the public each evening from 6.30pm, whilst spending the day focusing on their residents, cleaning the guest rooms and preparing the evening's menu.
But this causes problems. "As we are the only people living and working within close vicinity to Corrour Station, we really struggle with the public wishing to use our home and guest house as a toilet and waiting room during the day. We live here all year round, and even during our closure in the winter months we must lock ourselves into our home to avoid trespassers.
"We have, on several occasions, seen people urinating and/or defecating in our garden or behind the old signal box when we tell them our facilities are not for public use."
She said they would not have any problem inviting the occasional person into their home to use the facilities. However, there can be more than 70 waiting on the platform on a Saturday afternoon and they cannot risk their livelihood by allowing every person inside.
Ms Mackenzie added: "Surely it is not our responsibility, as a small niche business in a challenging location, to provide waiting facilities for rail passengers. Yet we are regularly verbally abused by people who feel it is our responsibility. This is having a harmful effect on our business."
She suggests at the very least, the addition of a vending machine and a toilet, and an improvement to the 'waiting room', which is just a small wooden shack like a bus shelter.
A Network Rail spokesman said: "The facilities at Corrour Station are under review and we are looking at various options as to how we can improve them. We will contact the residents directly to discuss our plans."
It is not the first problem Ms MacKenzie and Mr Bennett have had to face. At the end of June 2012 the West Highland rail line was closed after a freight train was derailed by a landslide at Loch Treig.
Eventually, the freight wagons were put back on the track and taken a little bit down the line to wait for their redeployment. But their resting place was right outside the restaurant, blocking the entire view of the restaurant from the train travellers that provided their main line of business.
Corrour station came into being after Tory politician and philanthropist Sir John Stirling-Maxwell of Pollok bought the Corrour Estate in 1891 as a hunting estate, where he entertained guests from the south.
He allowed the railway company access to his land on condition that they built a station at Corrour, which opened in 1894.
Sir John's guests would be met by a horse drawn carriage that would take then to the head of Loch Ossian, where a small steamer transported them to his shooting lodge at the other end of the loch.