There are trains from London's Euston Station to Edinburgh or Glasgow, both beautiful routes as you reach the rolling moors of northern England, as well as overnight trains to the two cities and Fort William.
Some cottages expect guests to bring their own sheets and towels, so check when reserving.
There is train and bus service on the Highlands, but it's infrequent, so you must plan. Roads are well-maintained but narrow. It is sheep innards cooked in a sheep's stomach, but tastes better than it sounds. This helps you forget the haggis.