I do not fly the CASA, but my understanding is it performs very similiar to a Cessna Caravan in most areas. Typicially the carry around 5000LBS and a 2-3 hour fuel load with crew. Because of it's max t/o weight it is regulated to the books performance charts for T/O performance. In the States anything over 12500LBS requires the adherence of the book, and anything less is pilot judgement.
I have flown a little on "The Chain". The terrian is well I don't know, we only went when the WX was bad or in the middle of the night. Medivac stuff in B200s, and we always were sweating fuel and alternates. The weather changes quick and usually for the worst. kind of like southeast Alaska without the trees and horrific weather. I guess par for the bush.
Bummer on the flying scene over your way. Where in Canada are you? My father is from Halifax, although we have not been back in years.
Mike