Sounds like there's a real possibility that it could complete its journey in a smidge under 5 years then.
Remember that it cannot travel by motorised transport where it is possible to cycle the same journey.
If we can't come up with a way to continue its journey without resorting to a train, maybe Wowbagger could, on reaching John O'Groats, take it to Orkney, put it inside a sealed food bag and bury it.
I just had a thought !!!!!
Once its journey is complete why not give it a new life on the Geocaching circuit? You can buy a "token" and then track it's journey via the Geocache website.
Do we have any forumites who combine Cycling and "caching"?