All-wheel in winter – mandatory?

We think about the purchase of a 911. Important (because expensive!) here is the decision “All-wheel or not”. I realize that all-wheel is probably better in winter than rear-wheel drive – but how is the rear-wheeler in winter? As climbable as once a beetle? Background is that it goes up to our house a short steep track, on which my wife with her BMW rear-wheeler always stuck. Therefore, it connects “back-wheel drive = stay hanging” and my arguments regarding G ewicht, rear engine, etc. are only received skeptically. Mind you, I came up with the BMW of course… Is there a few opinions? We will certainly not go to the Engadine with the 911 for skiing, it is more about middle mountain winter operation. Thank you, Miesmacher