In winter, you have winter backpacks. Summer backpacks may have some inconveniences, such as snow getting into the mesh, but winter-specific backpacks do not have such worries. Rather, backpacks that can be used in winter are built to withstand year-round usage specs.
The popular product from
Mountain Hardwear called
Scrambler is based on a climbing backpack. It is also suitable for carrying winter gear like axes (ice tools) while being simple enough for year-round use. Its suitability for urban use likely contributes to its widespread popularity. I visited
Columbia Sportswear Japan and spoke with Iori Kondo from the Mountain Hardwear product department.