I much prefer a manual in snow because I find it a lot easier to regulate power and obtain feedback about traction. But . . . vehicles with automatic transmissions can be very capable in snow and low traction. For starting from a stop in extremely slippery conditions, the technique I'd often use is to select a higher gear to start. This reduces the amount of torque transmitted to the wheels and reduces initial slipping. Instead of slipping a manual clutch, I'm slipping the torque converter or clutch bands. Do this enough - like when you're stuck and trying to rock out of a hole - and you can absolutely burn up a clutch band that is nearing end-of-life (done that). So just like slipping a manual clutch, it needs to be done sparingly.
I used this technique everyday for several years driving to work in a '68 Plymouth Fury III in the early morning winters in Alaska. The Plymouth was a big 18' long 4-door sedan with almost no weight on the rear axle and a 318 with 230 HP up front. Going to work, I'd pull into a left turn lane that was aimed uphill with about a 3% grade. In Anchorage, the roads would get covered with ice and snow in October and stay that way until May. Left turns lanes were almost always polished ice due to lots of sliding stops, wild spinning starts (dumb drivers) and the heat of idling vehicles melting the ice and snow (which would immediately re-freeze). The technique to get moving without spinning was to manually select 2nd gear on the automatic transmission (or sometimes even 3rd gear in extremely slippery conditions ), let off the brake and let idle or a tiny amount of throttle get the car moving. There was almost always enough traction to move slowly - like at a slow walk. Try this in Drive (which would select 1st gear to start from a stop) and the tires would immediately break free and spin in place. Less informed drivers could hold everyone up as they madly spun their wheels, going no where through two or three light cycles before finally getting through the intersection by dumb luck.
