We hunt the Mississippi use 2 long lines of 12 and 2 of lines with 6 with about 2 dozen singles. When it gets later our 2 12 decoy long lines get changed to all drake Goldeneyes. Sheet ice can be a problem you,ll have to break it up to smaller pieces and on occasion clean off each decoy they collect ice and slush. We hunt a shallow sand bar and it can be work. In deeper water with a boat and motor you,ll be out there often breaking it up if there is no chop. Even on lake Pepin it gets flat more than you would think the flow is less because of the width of river there so the ice doesn't move as quick a little less breaking up on the ice sheets but more on the decoy cleaning. We will even get slush on our decoy lines down below the surface.