I am real familiar with that portion of 219/86. Take I90. If its bad, you want to be on the interstate, not in the mountains (hills). There is a reason ski resorts are off 219 and not off I90. That part of 219 and 86 is a snow belt. DO NOT consider that route in bad weather. 86 in and of itself in bad weather has some challenges (like a .5 mile bridge over chatauqua lake).
If you need an alternate route, I have taken route 5 from Dunkirk exit to Buffalo when the thru way closed. I am an experienced snow driver, and I know the area, so even though I was closer to lake in a pure whiteout I knew it moved, and a few of us took that route when thru way closed that night.
So taking route 5 from Buffalo into Erie, then to I-79 south is an option. If you hit bad weather, avoid Pennsylvania (re-read my posts above). You may not understand how "bad" that is until you do it once. I would much rather deal with the 401 and head to windsor than to risk a snow storm in PA. The extra day on the commute is worth the safety.
Most of my winter traveling is based on visiting family in Buffalo at xmas time. PA is the worst part of the trip... even though (for me) it is 40 miles of a 400 mile trip, that 40 mile stretch is really bad (it is up on a bluff, so it gets dumped on if any front comes off the lake), plus PA does not plow it much. You will know when you cross the state line just based on quality of the roads.