I know North Gate is a bit tougher but the few times I doubled I appreciated the change of scenery; start on SG to the top, go down NG, and come back. You can still bail out of the Junction on the second try if you have enough of it.
Take it easy, stop for water refills if needed, just set your mind for the distance not the time. Gels or blocks (chews) are fine.
If the day is sunny start as early as you can, it can get very hot on the climb around 11am.