Well, the Subaru got stuck (due to clearance) while trying to get out of my spot. After backing up a little and only a minute of shoveling or so of shoveling I was able to slowly extricate myself. It was a little embarrassing having to explain that it was the tires causing the issue when asked, "isn't that thing AWD?"
I had a very similar issue, though worse, a while back in my STI with aggressive all-season tires. The three limited-time differentials (center fully locked) and vehicle dynamics control applying brakes as needed did not help, since ALL FOUR WHEELS HAD LITTLE TO NO TRACTION. A set of WS-70s fixed that.
/digression
The Civic, which was parked next to the Subie, took the same path without any issues. The tires spun, but with a steady, light throttle I kept moving forward through the worst and deepest, and was soon in the clear. I waved to my neighbors who questioned the snow-prowess of my Subie and explained, "it's all about the tires!" as I drove by.
The Civic was the only car in the lot that did not need assistance getting out (except for one or two who were plowed and shoveled out and had a slight downgrade to help them.)
If I can't find a cheap set of wheels this wiring or summer I'm going to bite the bullet and get a snow setup on the Subie, even if it's costly.