I'm not a pilot, I have not been to Yellowknife, nor do I pretend to have any knowledge of surviving an emergency plane landing. That said, I live near and recreate in the boreal forest. It seems to me there are other options available to you besides treetops and open water in that environment .....peatlands and brushlands. Where I live, and north to the edge of the Arctic, there is a lot of it. Mostly the surface is flat, spongy, and wet, and if there are any trees they are just small stunted tamaracks, or tag alders and swamp willow shrubs.

Walking out would be tough but doable by stepping on the sedge mounds. You would probably not want to try walking out anyway, as your plane would be easily visible from the air, and I would think that the local DNR or SAR would have vehicles that are made to travel in peatbog and muskeg. I know they heve them in this state.

Bug spray/head net or full bugsuit and water filter would be helpful to you.