Iowa ebike user here.

They’re “usable” to a certain extent, but range is cut by the cold and the wind on your skin is murder. Also, of course, you should never ride if there isn’t sand on the ground for your tires to grip or (even better) you have studded tires - even the smallest patch of ice can be disastrous.

But you can totally do it. I got some strap on arm guards for my handlebars and my helmet has a visor to block the wind, works pretty well.

Depends on how your local roads/side walks/pathways are maintained. If the snow is cleared, e bikes work just fine, but your range will be hurt a bit. A bad headwind will also mean your range goes down a lot (wind seems worse in the winter where I am, but that could be some sort of confirmation bias). The times I’ve biked through Blizzard conditions/extreme wind and cold I was very glad to have the e assist on the bike. Those days are rare though, and the primary consideration in my mind is how well things are maintained the rest of the year.

That being said, a path that hasn’t been cleared in days is basically unusable for any bike. Maybe a fat-tire bike could work, but I don’t have experience with that.

In terms of space, I use my bike all the time so I’ve made space for it in my apartment.

Maybe is should ask, what type of ebike are you looking to get? There is quite a range of types. Mine is basically just a normal bike with a motor assist.