My two cents...

If you get into trouble with loose-pack, move your weight off the handlebars and rest it on your pedals only, get your body lower and bum over the back wheel, don't steer quickly instead make very small adjustments and wait for the bicycle to correct itself while you focus on staying upright and pedaling.

With loose-pack caused by cars, studded tires won't help you because the studs can't reach the pavement. You compensate by having a lower psi in the tire helps to make the tire grip since your tire/snow contact patch is larger. Loose-pack snow is hard to deal with not only because its structure has been changed from being compacted making it more slippery, but because it tends to clump up and slide along underneath your tires when you brake or steer. It the same phenomenon with glare ice, some studs won't help you because they can't get through to the solid ice instead they glide through the half frozen sun melted ice on the top, this is even more slippery than loose-pack and very difficult to maintain balance on.