Spread straw or erosion fabric to cover bare soil and prevent erosion. Otherwise, you have a few possibilities but no guarantees. Check the forecast. If warm weather is predicted for a few weeks, perennial rye can germinate in as little as three to five days, and germinate and grow at temperatures as low as the upper 30’s. But — and it’s a big “but” — it will not grow much, and it will be so immature that it can be damaged by freezing temperatures, especially when there is no snow cover to insulate it. Sod is a dicey option but may work in a mild winter. Spring is the second best time to seed, from early March through April. You’ll need to overseed next fall.