I've been in very, very few stucks that I couldn't get out of with a shovel.
Last year, while riding at Lost Lake AK I had to dig a hole that was big enough to park a car in, just to get out. Once I got down to traction I drug the sled over to it and then built a ramp out, packing it with a shovel. My buddy's couldn't find me I was so deep in. I sat down, had some water and some beef jerkey to let the snow set up and then just rode right out.
We ended up digging a 100' long ramp on that same ride to get a guy out of a one way gully. It's amazing how much powder you can move with that little shovel.
I have even gotten unstuck and headed up hill with a shovel. Just dug all the snow out from around the sled, scooted the track over and filled the trench, packed it all down and rode right out.
See the common thread here? SHOVEL!! I never ride without one and I very rarely even attempt to lift my sled..it's hard on the back.