All my Sabals are in my back yard and that's where all my Sabal volunteers have popped up. Except one. The single outlier actually popped up in a very advantageous spot. In my FRONT yard, flush up against the front brick wall of my house. Every fall, it's easy as pie to mulch it up. I'm 100% convinced that being right up against the bricks has kept this thing going strong even through all the so-called vortex winters we had. Those winters wreaked havoc with my marginals, but not with the wall-clinging minor! It emerged in spring with just a tiny bit of tip damage. Otherwise, A-OK.
Even though this is a north-facing wall that gets zero sun in the winter, the bricks probably are a bit warmer than the outside air on single digit nights due to the warmth inside the house. If the outdoor temp is 1F, perhaps the bricks are somewhere in the 5F to 10F range. And that might be just enough for the Sabal. I think the same advantage applies to the roots as well. The soil temperature right up against the house must be warmer in winter than farther out in the yard.
That Sabal seed didn't get there by itself, but my goodness, was it lucky where it got deposited!