super737,
I think I was actually suggesting that a 767 was indeed viable on the route. The rule of thumb as I understand it, is that once over 80% load factor, a larger aircraft will be considered. A CO 762 actually carries about the same number of passengers as a CO 752, while a 764 carries about 20 or 40 more depending on configuration. So the 764 sounds like a sensible growth strategy for a route like BFS and frees a valuable 757 for further expansion.
As for the 'regular closure' of BHD, anyone who reads this thread will know that a diversion from BHD to BFS is not an uncommon occurence.