If the sleeper arrives in Inverness between 30 and 59 minutes late, you'll get half the fare back, and if it arrives 60 or more minutes late, the full fare back (for your journey on the sleeper between London and Inverness), without question. Generally if you've got an advance ticket for a connecting service to Kyle or Wick, the sleeper staff are very good at endorsing this for the next available service (usually they'll scribble on the back that the sleeper was late, which will entitle you to travel on the next available train); if there is no convenient connecting train, they may even arrange for a taxi to take you to your final destination (or so far along the route that you'll catch up with the train- bear in mind that the Kyle and Far North are not fast routes). I have never been to Wick, but twice when I've had connections to Plockton on the Kyle line, and the sleeper has arrived so late that I've missed the connection, the staff have arranged for a taxi to take me there. On the first occasion, the sleeper arrived 40 late and I was put in a taxi; we caught up with the Kyle train at Achnasheen; on the next occasion, the sleeper was about 110 late, and the taxi took me all the way to Plockton. This was presumably all at CS' expense. What I would suggest is that you advise one of the sleeper hosts in person tonight that you have an onward connection and get them to make a note of it; that way they'll be in a good position to help you in the morning.