Afternoon ferry to the Orkneys (£16/17 from either JoG or Gils Bay); ferry to Aberdeen (£24, @ 2300) gets in 0700 (ie morning after finishing). Lots of bike shops in Aberdeen who'll let you have a cardboard bike box. Send them an Amazon package of 5m of pipe insulation, 5m of 60cm bubblewrap and some packing tape. Post bike back and fly south though i was lucky Virgin to Heathrow allowed a sports equipment bag extra free (ticket = £56 six weeks ahead). Or forego boxing up and take bike on train (without Lejog competition cf Wick/Thurso and even Inverness).