I drove to the alps earlier this year on 235/40/19s in my TSI 280 estate. Bought some cheap(ish) winter tyres as dg360 suggests and they were great, but also bought a secondhand Thule K-Summit K34 snow chain set which were £200. They ratchet on to a wheel nut and spiderweb round the wheel from the outside, dont go inside the rim at all. Bit belt and braces with the winter tyres to be honest and I didnt need to use them but they were there just in case monsieur le gendarme had a pop as I think snow chains are mandatory in blizzards. The resort we went to the roads were cleared by the morning after heavy snow (Les Gets) and the winter tyres coped with everything anyway without a single slide.