Getting the fire started is a 5 minute one time project. After that you can have someone add some wood when the fire gets low (click on it to see how much time is left). When you're down to 1, 2 or 3 hours, someone can get more, then get back to "real" work.
Be sure to be the guiding hand and have your younger children collect every mushroom and seashell and butterfly they can. Mushrooms add to the food stores, shells and butterflies that are duplicates add to your tech scores. Keeping the fire lit also helps to gain tech points. When children reach 14, they can start learning to farm or research as well.
Keep after it. The game is definitely "win-able", you just have to be patient and priortize properly.
Tess