The water from the lake is the hardest part. The pipe has to extend below the annual ice average so it continues to pump in the winter. Thats the hard part. My best suggestion is to have someone drill a shallow well. Many times around lakes, the wells only need to be 15 to 20 feet deep. Relatively inexpensive when it comes to wells. Once that is done, you need to run the water into the cabin below the frost level. Depending on what area of the globe you are in, it can be as low as 4 feet. Upper midwest is about 4.5 feet. North east coast 2 to 3 feet. If you do not get it down below frost, it will just freeze in the winter. No amount of insulation will provide heat to an already cold water supply. The other option is to heat tape the water line, but heat tapes fail. As far as the piping in the cabin, you have to have enough insulation in the walls to not overwhelm your heat source. Its a balancing act. The more insulation, the less btu-s you need from your heat source. The less insulation the larger the heater to keep the pipes from freezing.