Due to time constraints, I'll only have 4-5 hours to drive around CBI - what are the must-sees on the Cabot Trail and is there a 4-5 hour loop route you would recommend?
From where are you coming and to where are you going afterwards? Then we may be able to suggest something.
In theory you can drive the entire Cabot Trail loop in under four and a half hours. But that does not allow for construction (which there is) or traffic or time to pull of to see the views.
It is a real shame you have so little time for Cape Breton. Are you taking the ferry or bridge from PEI? From where will you be coming on PEI? If it is the Charlottetown area then if you time it correctly the ferry is faster.
Here are a couple possible routes with times. Remember these times are quite optimistic:
https://goo.gl/maps/SrESA33vS952 This would be my preference