With the departure of Flybe from the Inverness - London route (...and by extension British Airways too, as a code share operated on the route), there is now now a huge opportunity for a carrier to pick up lucrative Inverness originating long haul traffic.
Little Red could use one of their MAN based aircraft to start the day at INV, and fly INV-LHR (via MAN) to capitalise on this gap in the market that has opened up. The extra traffic could also support the MAN-LHR part of the rotation.
There are plenty of well heeled locals in the north of Scotland, and even more Americans that want to visit, that now have to travel from ABZ/GLA or EDI. A feeder from here onto VS trans-atlantic services ex LHR should do very well!
Sorry, with a population density of less than 5 people per hectare, the Inverness route is never going to be "Lucrative".
Now if SRB wants to run a feeder service to take his mates out to the Caribbean, he may choose to do that! But he ain't gonna make money!
See the link for a population map.