Thank you for your question, Laura.   The reason for planting woody plants in the early/late fall is so that their roots can expand into the surrounding soil over the winter.  If the soil is too dry/waterlogged/cold/compacted, the roots can’t absorb water and nutrients.  Topsoil is “workable” (loose) more than clay.  I don’t know which you have.  Assuming you have good drainage, watering the plants over the winter helps insulate the roots.

A blanket will protect above-ground tissue somewhat, but mulches help the soil retain heat.  So, planting them now is risky—and this is predicted to be a very cold winter.  Good luck!