In another thread I was challenged to illustrate a trailer I designed in Arch 101 in college. I'm putting it here where it's more on-topic.
One of the profs was from Minnesota and he described the ice fishing process and they turned us loose. The requirement was two seats on either side of a 12" square hole in the floor. Some other's designs involved 8 or 10 4x8 panels that had to be dragged onto the ice and bolted together.
Mine was a light trailer that could be hand pushed onto the ice. The center of gravity was to be near the seat level so it would rotate on the axle until it rested on the bottom of the frame, then an additional push would stand it on it's end. The frame does double duty as the door frame and the seats are anchor point for the suspension upright. There is a rack for poles opposite the door.