Scruffy, as has been pointed out your small airline must be the problem, maybe the added snow will help insulate the hose enough to allow the warmer air from the pump to keep it open.
My linear pump is only 80 watts but haven't had any problems. It is connected to a 3/4 inch air line and a 50ft. soaker hose which is coiled in a loop, similar to what you have.
12 below this morning at the pond but the aerator is keeping an opening.
