This is just speculation as I have not done too much structure placement by ice.
I'm not sure that when you place some structure on ice that the structure will end up in the same place in the pond. When ice melts, doesn't it sometimes break into pieces, and then move as the pieces shrink? And I am not sure if the ice remains level with weight (what you've placed on it) as it thaws; won't it tilt as some point, thus letting the structure slide off?
Just questions here.
