BC is my home. Given the time of year the trench would probably be my last choice. This just because it's a very long hop with very little on the ground below, and because it's early season a fair few of the possibilities may well be uninhabited and/or not have fuel if you need it. Then there's the spring weather in the Rockies, and the trench has unpredictable/poor weather at the best of times. I wouldn't pack fuel in the baggage if it can be avoided by taking a different route. If you do go through MacKenzie there is 100LL there, call Jim Bellevance at Trench Aviation 12509971551. Prince George has usually about the worst price on 100LL, I would try to fuel anywhere else, you have options being on wheels.