Someday I will break down and get snow but the amount of time that the Mini will be my sole car is dwidling which is why I am resisting.

Anyways... I currently have 215/45/17 Conti Extreme contact all seasons and the car in unplowed snow really seems to want to drift all over the place. It just feels really unstable in the 3-4 inches of show we had today. Traction was okay as I never got stuck but it does not feel sure footed at all.

Does that have to do with my wide tires and what is a good compromise size for the winter?

 

I would say that this is normal traction in 3-4 inches of unplowed snow for this vehicle.

Narrow tires are always better in snow. Dedicated snow tires are better in snow.

I've got the stock 16's on right now with dunlop run flats. We haven't had any real snow here to speak of so i haven't had a chance to get out and really experience winter driving yet (bought car in July0.

I've also got a set of 17's and have been contemplating on purchasing your tire or going to a UHP summer tire on them.

 

I've gone with a 16" wheels and snows by blizzaks. I think they're great.

 

How does it feel other than traction? Does the car move / feel unstable when going over unplowed snow or deep slush grooves?

 

I'm running Nokian Hakka 2 snow tires, sized 185/65/15. They are narrow & knife through the snow & slush very well. On my 20 mile freeway commute this morning I had zero problems. I was able to maintain 55 mph with no trouble. I love passing those SUV's.

IMO your tires are too wide for the conditions you drove in today.

 

Of course you drive a bit more careful in the snow, but the car seems very stable in snow and slush. I haven't driven it hard on several inches of snow, but I can say that I've used blizzaks for years on my other cars and they make a big difference.