Smelting,
An Indian would let the smelts run and spawn and then catch them going back down the stream.
Before dawn rock up a narrow section on a small stream all except one or two places where the water can flow. The smells will start to head back down stream just at dawn. Stick a net in these holes where the water flows and the smelts will swim right in. No fuss no muss. They will not turn back up stream.
Ice fishing,
They had several ways. One way was to take a small fir tree or other softwood, chop a hole in the ice and stick the tree upside down into the water so that the top would give good cover for bait fish. They would put bait fish in and they would stay close to the top of the tree for protection coming out when it was clear. This would attract large fish. The indian would then fish next to the tree top.
Keeping warm in a tee-pee
The original rocks around the campfire trick. The rocks would collect heat and give it off slowly when the fire went down. One of the main ways to find indian sites is finding fire cracked rocks. They would also bank the fire so they would not burn too fast and use plenty of rocks.
Keeping fish fresh in the winter
Again a no branner for an indian. Chop a shallow hole in the ice. Lay the fish in the hole and then fill it with fresh water. They will stay frozen and out of reach of any animal until they wanted to eat them. They did this with moose and deer too.
Movies show how indians suffering through winters not having enough food. Think about it. Deer yards were like meat on a stick when the snow was deep. There were plenty of fish in all the streams and lakes.
Large fish weers have been found. One in Newport, Maine has been carbon dated to 5000 years ago. It also showed that the weer had been maintained for many generations of indians. So these indians would gather together catch a bunch of fish smoke or freeze them and have fish all winter if there was nothing else. Then in the summer some would head to the ocean (where we have now found huge shell heaps) and stay all summer on the beaches. Others stayed inland and grew corn. When whitemen first came to the Canton Maine area they found 100 acres on Maze growing there. Sounds like a tough life doesn't it.
Give me a nice indian woman some kids a canoe, a warm tee-pee, a place to grow food, plenty of fish and other game, friends close by and you know I think I could make it.