Cold-Tested Grease for Rear Hubs

I just had my Mukluk built up with ultra-fancy-blingy Six 1 Six hubs, made in Grand Rapids, MI. They come packed with 'Morningstar Soup,' rated from -50 to 140 F. Herein lies the problem.

(Winterizing is putting very little extremely thin grease/almost no grease at all on the pawls in the rear hub so they engage at 0F & colder. If hubs are packed, per se, with any grease, the extreme cold causes the grease to gum up, which prevents the pawls from engaging.)

I left my bike in the back of my van during the day, while parked at work. When I got it out to show a co-worker at the end of the day, the rear hub didn't engage - it slipped many times - meaning the pawls didn't catch, i.e., the grease used to 'winterize' the hub doesn't work/there was too much grease in the rear hub. It was -15F, not -50F.
I went straight to the LBS to find a friend who built a set of fat wheels with the other set of hubs that came and he had the same problem - lots of slipping and failing to engage.
After this, I went on two different -5 to +5 F rides and had my rear hub fail to engage, continually, many times on each ride. 

As it turns out, Six 1 Six simply injects their hubs with the Morningstar Soup, inundating the hub with it and forcing out all the normal grease. This means the hubs are literally full of grease, and, therefore, will not work in the cold. Even though the lube is rated to -50F, there is way too much in there and it needs to be removed, leaving a very thin film of grease.

I've heard a lot of contradicting stories this past week about Six 1 Six, Soup, and both's effectiveness/quality.
All I can say is shops in Anchorage stopped using Soup and there are internet stories of Six 1 Six hubs 'shitting the bed shortly' after being built, but one extremely accomplished rider has used Soup on at least 6 ITIs down to -60F and Lubriplate Mag-1 grease has been proven to work for over a decade in the coldest temperatures.

My hubs are now sporting a thin film of Mag-1, winterized by hand, not by a syringe.

Make your own judgements and 'wear some comfy walking shoes.'