I guess opportunities for Scot move on just like they do for everyone else. The key is to keep on top of things and strike after new business opportunities when you see them.
Scot have had two aircraft out on lease to other scheduled carriers, one to CityJet for LCY to Belfast, and one with BMI for a range of routes from Leeds. This sort of work keeps many another airline going as well, as Titan or Flightline will tell you. And they have never aimed to employ all their fleet on schedules as they pick up a lot of charter work as well, particularly high-end customers such as major football teams, for whom a 30-seater is ideal and there is not a lot of other capacity of this size around.
The Dornier is out of production now and given the number parked up round the world the lease rates for what is still a very capable and presentable aircraft must be low. The vast majority of the costs will be hours-related, it makes sense therefore to only fly hours which are adequately remunerative.