A6 Avant vs XC90

Hi! I’m driving an A6 Avant (BJ03). Unfortunately, no Quattro, which was a problem last winter. That’s why I want a “more winter-friendly” car. I’m fascinated by two vehicles: the XC90 D5 and the Audi Allroad, each with automatic, how can I compare them best? Which is more terrain-friendly? I think the Quattro system is basically superior in winter, right? Terrain suitability is not important to me, it’s only about the use in the snow. Does anyone have comparisons with the maintenance and running costs? After the space in the A6 gets pretty slow, the question arises further whether the XC90 has more space and is better to use? Thanks already in advance for your answers, Thomas