Given your snow depth, my first choice would be a snow cave, although time and terrain could be an issue. A quinze could be considered, as well.

Your question is a bit general. You specify "good gear," which to my mind would very likely include a tent; it most certainly would contain an adequate shovel. Even without a tent, certainly a bivvy sack would be there. Doubtless there is a stove as well. My second choice would be to deploy the bivvy sacks in a sheltered location, perhaps build a wind wall and try and provide overhead protection; otherwise periodically dig out from under the snow.

Are we talking mountainous or flat terrain? Are avalanches an issue??

What would be the differences between a shelter for SAR workers vs a stranded day hiker (other than size, most likely)? I'm just curious.....