Not only are some footways snowplowed, but the others return to a usable state just by other people walking on them - although, naturally, not for the elderly. And that happens within a varying time; some have so much traffic that they’re mostly usable within hours of a snowfall, while others might be full of untouched snow still few days later - or even though the whole winter. Somewhere in the wiki the tag ‘trailblazing’ was mentioned for snowplowed ways, used as an sort-of-alternative to seasonal:winter=no …

The maintenance priority could be entered, at least with local knowledge, but is something that would benefit from a list of promised/intended service levels, as in how the maintaining authority has defined the levels. Which might range from “snowplowed within an hour of snowfall and once every four hours in continuous snowfall” to “when all other roads have been cleared, which could be up to a week after the last major snowfall” (and in practice could be even later than that).