The gascolator captured a lot of the water.  Don't know what would have happened without it, but I suspect the partial power loss (due to the screen plugging with ice crystals as best we could tell) could have turned into a complete loss due to water ingestion.  I don't think the engine could have passed that much water before we got to the ground.  After landing, with temperatures above freezing, the engine ran okay even though the gascolator was pretty much full of water.  One lesson I learned was that even though the gascolator will likely contain no water for hundreds of flights, when it needs to trap water it will do it.  We found the same sort of thing about fuel filters in cars - typically they will go for a 100,000 miles and not trap anything, but if you get one bad load of fuel it can fill the filter, protecting the rest of the system.  99% of the time it isn't needed.  In my ES I installed the largest gascolator I could find and put it in a location that allows draining before every flight.  But, of course, so far haven't seen a drop of water in it.  I still like it there.