Others, I'm sure, feel differently, but in expediting I think winter tires are a waste of money. For the most part, after it snows the roads are cleared rather quickly, so you aren't driving on roads where you actually need snow tires. Granted, even days after the main roads are clear, there can be some secondary roads and shipper/receiver lots that are pretty rough, but good all-weather tires with at least 6/32 of tread can handle that, generally speaking. If your expediting life keeps you running anywhere between western NY/PA, Michigan, Chicago, Wisconsin and Minnesota, then snow tires for the winter is probably a good idea. But more likely, the overwhelming majority of the miles you put on your snow tires, like 95% or better, is going to be on asphalt or concrete that is free of snow, which just wears the tires out quicker.
I've had winters where not once did I drive on snow covered roads. Plenty of snow off the roads, in the fields and yards and everywhere else, but not on the roads. I've certainly been in situations where I wish I had snow tires, but those are few and far between compared to the times I was driving on clear pavement. If it's bad enough that you shouldn't be driving, snow tires are not likely to make the difference in expediting. Living and working in Duluth, MN, yes, in expediting, not so much. If it's that bad, pull off the road and wait for the roads to be cleared.
If I had to make an estimate, I would guess that, on the average, there are probably about 10 days per year (Dec, Jan, Feb, Mar) that I wish I had snow tires on the van. For me, that's just not enough to justify snow tires all winter.
If you do decide to get snow tires, get four of them. Mixing snow tires and all-season tires on the same vehicle causes the front and rear axles to have unequal traction and control. That seriously impacts the safety and handling capability of the vehicle, especially in emergency situations. Having good traction on the drive tires, but not being able to steer, kinda defeats the whole purpose of having snow tires in the first place.
Since this will be your first winter expediting, I'd suggest just going with some good all-season tires, and by the end of December you'll know if you need to buy snow tires.