Marc, are you still going to have the expedition if the marsh is not frozen? It might be iffy if the current weather pattern continues into January.
If you don’t have this the same weekend as the Waukesha Janboree (January 20th) and the marsh has a comfortably safe layer of ice on it, I would be willing to make a return trip to the Navarino area to grab this one.
Is this thing on for the 27th Marc? The 10-day forecast shows no days above freezing until next Saturday. And if the ice is not in good enough shape, there is always the long (4 mile) and dry hike to the cache…