Mouse
The snow hole thingy is so dangerous some places that its good to bring up more. A hole is created under a tree by stopping the snow and the snow builds up around the tree. Camping under a fir tree is probably safe because sloughing snow will slide to the side and make the surrounding snow deeper. Now - how do you get out of the hole? Worse is snowboarders who land in a hole headfirst - they car suddenly in a survival situation. Trying to free yourself and can make you sink in further like quick sand.

Even hiking through a flatland forest has many snow dangers. You can step on a weak spot, like where a tree in close to the surface, drop 2 feet and find your feet hopelessly trapped.

Stepping next to a large rock with snow around it? The snow next to the rock will melt creating a trap. When you step on it, you drop in, and pack the snow around your boot instantly. I had to call my wife once to come over with her iceaxe to chop my boot out.

Walking through a flat land forest you take the little narrow bridges in the snow between trees and they can collapse. Backcountry skis provide a great deal of security as do snow shoes, but snowshoes bridge a shorter gap than skis.

Steep snow - without a hiking pole, ice axe, or self arrest device of some kind, if you fall on a slope and start to slide, it may impossible to stop before coming to a very fast stop.

Its best to not travel alone in the winter unless you stay on groomed trails, which is sort of a special case.

Its best to not go off trail too much in snowshoes either unless you are pretty savy about winter travel. Carry the "ten essentials" including an insulated pad to sit on.
Jim
ps TomD you did well. Sorry you remember the trip as one where you were miserable.