Scott is right on all points. Prudence is required. A fat tire bike, maybe. Back country skis, likely. Snowshoeing, very likely. Beware that icy conditions can be dangerous. And it may not be possible to get a rescue vehicle in to get you. Also, cell service can be spotty in the park. I'll echo what Scott says; ask at the entry station before making any attempt. If they advise against then you shouldn't try it.
Are they really going to tear down the tower?
Check at park office
You have to take the ice age trail up because road is snow mobile trail and stay off ski trails. Check at park office on your way in.
I'm not sure if they close tower for winter, but I wouldn't do it if its a lot of snow. It is scary (at least for me) at it is.
Thanks! Your answer is awaiting moderation.