Heidi's worries were actually sensible in this situation, because in the outlook of the overwhelming majority, even in the reality of this era, winter only meant one thing: everything withered; life gradually dwindled; all work ceased. Humankind would store enough food and fuel before this, then stop work, return to their homes, and switch to a pure consumption state.
Just like the animals that stored food in tree stumps in advance and hid in caves to pass the winter.
