"""The enormity and cost of the project"""

...not if you use flexpipe gasline made in Alaska.

Gasflow = Cashflow

Build a small flexpipe from Nslope to Livengood first.
This will start moving a valuable amount of gas for not more than $500million CAPEX. 
The first small flexpipe will pay for the 2nd flexpipe in just a few months. 
Small is beautiful, plant the seed and let it grow.

A big whopper megapipe is a National Security risk, a permanent "Kick me I'm Stupid" target.

Start now, and by 2020 we will have built enough flexpipes to move 5bcfd of gas in a dozen flexpipes. Flexpipe gaslines will almost never suffer a 100% system outage unless during all out nuclear war. A megapipe gasline can suffer a 100% shutdown if a rat chews on the wrong wires.