Thanks for the responses. I did take advise in emptying ballast as best I could. This could be a good case study on the topic. Much I've read is what you SHOULD do and what CAN happen. I put myself in a bad situation and have an actual positive outcome, I think. After nearly four days of temp highs at or around freezing, the lake began to freeze. I checked ballast on fourth day and I had about 1/2" freezing internally, matching similar to about 3/4" lake ice that had been formed. I didn't prepare but had a small Sunbeam area heater. I put it on full blast overnight inside cabin. I came back next day and that heater had heated up hull enough to melt ice all around boat by 3' as well as internal ballast. I proceeded today with rigging a 1" tube to end of my shop vac and pulling 200+ gallons of water from the tank, 6 gallons at a time. Worked well- just took some time. Now I'm ready for rest of lake to thaw so I can haul out but I'm hoping with the heater on in the cabin and a nearly empty ballast, I should be okay. Incidentally, as I pulled water from ballast I continued to check for water leaking through ballast drain. I felt no pressure building when plugging air hole and don't believe additional water is coming in through drain as some have hypothesized. One other note was that I never treated the ballast tank with any chlorine and found the water I extracted to be very clear and odor free.
Finally, while I need to see next spring if any real damage occurred, the water in the ballast did actually freeze similar to the lake, not really faster or slower or at majorly different depths. And, it seems clear that if the boat interior and hull is warmed by cabin heat, the ballast water cannot freeze. This is all actual real experience I just had.
See attached pics.
Hope this helps all future procrastinators. Again, would rather not resort to these measures but feel there is some solid backup emergency things one can do if in a bind.
