I am in zone 8b, and we do have freezing weather. This year (I hate to use the word unusual) because it seems like every year is unusual, we had 17 deg. F. in early November. We had 18 deg.F.
a few days ago followed by several days below freezing. It is normal to have a few weeks in the winter where we get freezing temps, but they are "normally" short spells and the temps. normally rise pretty fast during the day. The polar Vortex was very "unusual" I lost a lot of plants that year, but did not notice any Amaryllis that died and many had just been transplanted recently.
My plants are planted a little deeper I think than the normal recommendations, I do bury the entire bulb below soil level. The oak trees in my yard provide natural mulch for many of my plants, I use pine straw and leaves I collect around the neighborhood also, but no conscious effort to particularly protect the Amaryllis. I mulch mostly to build up the soil, but it has the side benefits of helping to keep the plants warm too. Of course this year may be "unusual" and I may lose a lot of my Amaryllis due to the early freeze. The polar Vortex really cost me heavily on Caladiums, and Gladiolus plants, but it could be a repeat this year or maybe not for the next ten years, just never know.
Some years mine bloom in March, last year it was April.
This one would not be liked by many because it was so short , but I loved seeing the blooms almost as large as the plants: