if they wished, plan their flights to remain in areas, or at altitudes, of known coverage.
I would fly to avoid visible weather, rather than follow a planned route. I always fly below the cloud.
Scottish Information are good - but only if they can be contacted. I find it difficult to predict where this will be, N of the Great Glen, through until the west coast. I often sign off to a listening watch with 127.275 as I leave the weat coast, but can hear Scottish in surprising places and altitudes before I call Inverness. Nobody is interrogating the transponder over much of the area, and our ELT got stolen from a vehicle.