I don't think I carried as much fuel as you think I might have. I carried an 11-oz bottle that can only be filled up to 9 oz I think. And I think I only had to refill it once. There may have been a night or two (out of the 16) when I was able to get running water, but otherwise I was melting snow.
The reason I had problems getting stakes into the ground was because the ground was frozen AND there was not enough snow on the ground to hold snow stakes. Just very different conditions than I expected, and I hadn't quite thought those repercussions through. (That winter Duluth had the third "brown Christmas" in its history, i.e. no snow by late-Dec.)
I definitely missed the really cold temps that winter, but you can't fault me for that -- I had no control over it obviously, and I had purchased my flights up there a month or two earlier.
Calculating a base weight for winter is really tough -- you end up wearing/carrying WAY more stuff in the winter that doesn't get calculated in base. And then there's a huge difference in travel mode too: the weight of a ski setup (skis, boots, bindings, overboots, skins, waxes, ski straps) is substantially heavier than snowshoes (snowshoes, shoes, overboots), and that difference right there would probably knock any ski setup out the arbitrary SUL number you identified.
Finally, what does the comment, "If I were sponsored like Skurka"...I could get all the most expensive gear... mean? I can almost promise you that about 95 percent of the people on BPL make more income than I do (I'm figuring that 4 percent of the users are Boy Scouts and than 1 percent is unemployed but unfortunately isn't getting unemployment), and being sponsored hardly has the perks you think it might. In today's marketing climate "being sponsored" means getting a few hundred dollars worth of gear from a select number of companies; and in very few cases (e.g. Conrad, Viesturs) does it mean getting a paycheck that allows you to buy whatever you want.