Roger,
The lake we lived on in Wisconsin had rather violent ice break ups since we 
lived on the far side of the mouth of the Yellow River. I remember seeing 
entire trees being moved across the lake and somehow they always managed to get 
stuck right in front of my house. Spring and summers were spent dragging, cutting 
and stacking the wood on our bank which was then used later the next winter 
for huge fires on the ice. 
It is no exaggeration to say we stacked the wood log cabin style and then 
filled the interior with wood sometimes twenty feet high. It was very impressive 
and drew people from miles for a really good party. And no, it never burned 
through the ice.
These days I'm content to have a fire in our fireplace when the temps hit 30 
degrees.
The winds are really howling tonight. Sailboats are breaking lose from their 
moorings and grounding and just recently I clocked a gust at 54 mph. It must 
be a cold front moving in after a beautiful weekend. Oh well, I guess winter 
isn't done with us after all.
Good luck on your dock project. Build another one and it will probably last 
another twenty years without incident.

Rummy