Was kinda thinking the same thing, but I'm a maritime guy who doesn't spend much time in -20 temps...
Questions for you Continentals...
Will snow crystals bond at all when temps are that cold, even if the temp gradient is relatively stable?
I can answer that one. Nope. Faceting must happen- how could the tg be stable with shallow snowpack?
In these high gradient situations, do the crystals tend to be bigger at the surface relative to ground, or the other way around?
The facets at the ground will probably progress to depth hoar (6mm or larger), while the nsf at the surface (duh) will remain small as the gradient goes back and forth, moving the same bits of vapor-deposition from top to bottom, bottom to top. Then in some places there may be surface hoar as well- a fine cocktail. Bigger facets around the pre-existing crusts.
No need for us to be rude to one another.
And Salsa, I saw what you did there with the comment about Rog

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