I concur with glc. At 3100 miles, this is not going to be any "45 hours". Google assumes that you can drive the speed limit (or higher) without stopping for fuel, traffic, to eat, go to the bathroom, or stretching. When we crossed the US, starting in CA heading east, it took us 6 days, driving about 500 miles per day. That was in the summer months and we didn't have to worry about the weather spitting snow or ice on us. With weather possibly causing issues, I'd allow a week, as glc suggested.