I've used my cargo tricycle on ice and snow, works pretty well up to about 2" of snow, then you can't get enough traction on the rear wheel to push all three wheels through the snow.
On a regular bike, you need friction with the pavement to stay upright. Lose that friction, and you're going down.
With a trike, you need friction to turn over. Lose that friction, you may slide all over, but unless you slide into a curb or something, falling over is not the issue.
Here's the cargo trike on some snow several years ago (this is a front-loading Worksman upright cargo trike, two wheels in front)::