Hi, neighbor. Massachusetts here.
During the time I had my two V8 E39s (540i/6 and M5), I also had a pair of VW GTIs. I ran winter tires on the Bimmers, and the all-season tires year round on the Dubs. In REALLY bad weather (especially if slippery), I left the GTI on the driveway and took the Bimmer. (Admittedly, winter tires helped.) But, the RWD cars were less likely to skid, the skids were less dramatic, and the cars were easier to get back under control.
My counsel -- get the M5, invest in a set of winter rims/tires, and enjoy the hell out of your European delivery. FWIW, I did mine a year ago. Many highlights, including two laps on the Nurburgring, and visiting TWO BMW factories. The Munich plant is across the street from the Weld, so that's easy. My F10 is my fifth car assembled at Dingolfing, so I wanted to see that, too. The place is HUGE. And it's a delightful drive from Munich.