Love your ideas / photos. I am in MN in Zone 4a. I found that my hostas in containers survive the winter ONLY if the containers are brought into the garage. I use hostas as companion plants in my Coleus pots. Particularly Golden Tiara.....it grows so fast that I take it from in-ground plantings, put it in really big containers (too heavy to move to the garage) and who cares if it doesn't overwinter...just get more next year from my many Golden Tiaras.