Isn't there a risk of damage to the boats if it freezes too much?
No, not really, as long as you dont try to move them, most of them are built of steel, with a typical thickness of 6mm, moving them through ice though, will very quickley remove all the paint/tar from the hull.
Yeah I remember living in the high deserts of California and leaving gallons of water outside our house just to see it frozen. My first snoe experience and our neighbor had to tell me to go back into my house and wear winter clothes on... I dont think it was even an inch of snow but i was hell bent on making a snow man. Sure it was more brown than white but damn it that was my snow man.