The fuel was gelling before it hit the filters. When it gel's, wax crystals form in the fuel. They accumulate in the filter, that's all.
Find out how the local fuel stations mix their fuel for winter. You may have to mix some #1 in yourself if they are not doing it, or some Powerservice or the like.
Up here in MN, the local stations all start mixing fuel for winter in Nov in stages. After 12/15, we're in full winter mode. Don't generally have to worry about it because the stations are on top of it.
2008 6.7 Quad cab SB, G56, 3.73, black, Edge Insight, 285-70/17 BFG, Bilstein 5100 shocks, MagHytec rear diff cover, otherwise all stock.