two quick things:
1) turn VSC off. Otherwise, VSC will apply braking to the slipping wheel, and also dial back throttle. VSC is awesome in many situations, but is exactly the wrong thing when struggling in snow (it is, however, fantastic once you're smoothly underway on snowy roads). 2WD and / or 4WD.
2) siped tires. You want a thousand sipes to "pinch" and hold little snow-towers. Then, these little snow-towers press onto, and engage with, the road snow. It is snow-on-snow that gives you traction, and you need to get this started correctly with a thousand little sipes.
Big open-tread tires will shovel snow and throw it for you, but that's usually not helpful. A tighter tread, and thousands of sipe-cuts is the answer. I've had pretty good luck with AT-tread tires (and of course, actual snow-tires). MT-tread not so much...
As for tire-width: Most people in most circumstances will be better off with taller and narrower "pizza-cutter" tires. The idea is to get through the snow, down toward asphalt so the little snow-pinches actually engage and couple your tires to the pavement. The exception is deep snow, and offroad - here, you may benefit from wider "flotation" tires atop the deep snow.
Summary: Tread and siping is incredibly important for snow traction. Width is the second-most important consideration. Avoid wide MT-tread tires. Keep VSC "On" once underway (may keep you out of the ditch!), but turn VSC "Off" when struggling in snow.
