well, unfortunately, my best advice would be to plant it in the SPRING. Spring planted gives it the whole season to put down deep roots and get well established to be ready for the rigors of winter. If it were me, I would pot it up and bring it in for the winter when it starts getting cold and then plant it in the ground next year.
Otherwise you have already named all the ways I know for winter protection: keep the soil covered, plant it in a warmer micro climate area like near a south facing wall or at least with protection from cold winter winds, cover the plant once it is dormant, be sure you water deeply late in the season before a hard frost.
Then hope for a milder winter. There is winter and then there is WINTER like we had last year. I'm in zone 6 also, but last year we had a zone 5 winter and a lot of stuff didn't make it. Farmer's Almanac, which correctly predicted last year's harsh winter, is predicting more of the same for this coming winter.
""Shivery and shovelry are back. We're calling for some frigid conditions, bitter conditions," said managing editor Sandi Duncan.
The latest edition, which officially goes on sale this week, forecasts colder-than-normal and wetter-than-usual weather for three-quarters of the country east of the Rocky Mountains. Drought-stricken California, along with the Pacific Northwest, will see normal precipitation and cool temperatures this winter, the almanac said."
https://www.usatoday.com/story/news/nati ... /14529295/