I went through this discussion in earlier threads on winter driving. My experience:
I tried very hard to keep my RWD going this winter without snow tires by using chains to get up my long steep driveway. It works but is a pain. We have had a crazy winter here: warm, very cloudy (unusual in sunny Colorado) with lots of snow and rain (rain? in January?). The rain turned parts of my driveway to glare ice for a time, something I haven't seen before in my 32 years in Colorado. Since roads here are plowed and sanded promptly, the vast majority of my driving is on clear, usually dry, roads. But my driveway and dirt road cul-de-sac are often snowpacked for long periods of time in winter.
At the end of January I finally gave up and bought snow tires (Michelin X-Ice 3), thus ensuring the end of the snow for this winter (and, likely, next winter as well). Despite the return of sunny weather, my driveway stayed icy for many days and the dirt cul-de-sac stayed snowpacked for longer, until it melted into deep slush. So, I found that the snow tires stuck very well to both ice and snow and helped with pushing through deep slush. Despite driving mostly clear dry roads (in the 50s and 60s F) most of the time, the snow tires sure helped with my driveway and cul-de-sac. As expected.
If you live in the flatlands an AWD car with regular tires
might be ok on snowpacked roads. If you deal with steep hills you need either snow tires or chains, regardless of whether or not you have RWD or AWD.
As others have said many times before me in other threads, a Tesla RWD with (good) snow tires makes for a very capable snow car. The modern traction control helps
a lot. Even on hills and curves. Would AWD be even better? Yes, of course. An advantage of AWD is that you can might get by with regular tires in moderate winter conditions on the flatlands. If you deal with serious winter conditions or steep hills and sharp curves, you would need snow tires (or chains) regardless of whether on not you have RWD or AWD.
All of this assumes careful driving in winter conditions. In Colorado, SUVs are notorious for being seen upside down along freeways because the drivers were going too fast for the conditions. Just because AWD can help get you going doesn't mean you can stop in icy conditions. (For my purposes getting going is the important part because my county is excellent in plowing and sanding the very steep roads.)
Would I buy dual drive for an extra $5000? Yes, for a number of reasons (handling, range, front regen braking). But RWD + snow tires is good enough IME.
FWIW.
^ Mountain Tesla, with snow tires, two weeks after being washed.