Eric,
Sorry you were discouraged by some of the answers. So let me share some of my personal experience.
This is with my own vehicles and my Dad's vehicles....
Rear wheel drive cars - Normally had "snow tires" (this was in the late 70's early 80's) and they were ok.... some did better than others, depended on how the car was built. We had several wagon's and they seemed to do better than coupe/sedan's we had.
Front wheel drive cars - Better in slippery driving than a rear wheel drive. One bad thing about front wheel drive, your driven tires are also your steering tires. If the tires are spinning they have no traction, so, no direction control (steering). A rear drive is spinning the rear tires, the fronts still can steer, in a front drive, they spin, and affect steering. If I had only the choice between a front wheel drive and rear, I would choose the front wheel drive...
2 wheel drive trucks/vans - Had a F-250 2wd RC LB and it would get stuck in wet grass, literally...in the winter, we would load up several hundred pounds of wood into the bed, left just enough room for the snow-blower to fit and it helped... was not perfect, but you could at least get around.... we have also had 2 E-150 Customized Vans, and they did better than the truck..... I think because of weight/weight distribution. The vans were heavier, and had more weight on the rear wheels.
4 wheel drives - 2 trucks and 2 suv's. An 83 F-150 RC LB LS-Both Ends, and a 97 LD F-250 EC SB - Much better in slippery conditions. The 150 was nice, but with the Limited Slip on both axles, it would go just about anywhere, but if there was a grade to the road (like a crowned road in the country) if it was slick, and in 4x4 it would slide into the ditch before it would go..... then it would go..... Another idea on the weight, on the 150, we had a topper/cap and a tonneau cover, I could tell a difference in 2wd traction with the topper vs the tonneau cover on, the topper weighing in at a couple hundred pounds (aluminum) and the tonneau cover being 5 or 10 pounds.... The SUV's a Durango and my Excursion. They they do well in 2wd again, I think because of weight distribution, and they had an A/T Tire instead of a street tread. A good example of what 2wd vs 4wd, if you have seen the pics of my Excursion, it is sitting in my driveway, not sure of the angle. but it is apprx 2 car-lengths and if I stand at the bottom of the drive, I am looking across the top of the garage floor and I am 6'4". I back into the garage, and I normally can get into the garage with the cars, but if it is slick, no matter what is making is slick, snow, snow-pack or ice.... when I get the front tires onto the driveway, the rear will spin (either SUV) put it in 4x4, and it normally will walk tight up the driveway.... again, I believe weight distribution.....
The key to traction is weight.... and "hooking" to the surface you are on.....
Another example.... I have a Cub Cadet garden tractor that I plow snow with, and I have chains on it. Numerous owners have tried many different combinations to get traction when plowing. Ag tires, snow-blower tires, or the normal turf tires, with and without chains. What has been found is, the turf tires with chains, and weight are the best. Reason being the turf tires are "flat" across the surface, which makes the chains have the most contact with the surface, and weight to make them dig in.... I my case, the tractor, blade and chains weigh in at about 1000 lbs, and in my winter gear I am about 375, so almost 1400 weight, and I can drive about anywhere when it is slick.... I have driven up the driveway after an icestorm, and didn't spin a wheel. So it is traction, and weight distribution....
